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Walker E, van Niekerk S, Hanning K, Kelton W, Hicks J. Mechanisms of host manipulation by Neisseria gonorrhoeae. Front Microbiol 2023; 14:1119834. [PMID: 36819065 PMCID: PMC9935845 DOI: 10.3389/fmicb.2023.1119834] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 01/18/2023] [Indexed: 02/05/2023] Open
Abstract
Neisseria gonorrhoeae (also known as gonococcus) has been causing gonorrhoea in humans since ancient Egyptian times. Today, global gonorrhoea infections are rising at an alarming rate, in concert with an increasing number of antimicrobial-resistant strains. The gonococcus has concurrently evolved several intricate mechanisms that promote pathogenesis by evading both host immunity and defeating common therapeutic interventions. Central to these adaptations is the ability of the gonococcus to manipulate various host microenvironments upon infection. For example, the gonococcus can survive within neutrophils through direct regulation of both the oxidative burst response and maturation of the phagosome; a concerning trait given the important role neutrophils have in defending against invading pathogens. Hence, a detailed understanding of how N. gonorrhoeae exploits the human host to establish and maintain infection is crucial for combating this pathogen. This review summarizes the mechanisms behind host manipulation, with a central focus on the exploitation of host epithelial cell signaling to promote colonization and invasion of the epithelial lining, the modulation of the host immune response to evade both innate and adaptive defenses, and the manipulation of host cell death pathways to both assist colonization and combat antimicrobial activities of innate immune cells. Collectively, these pathways act in concert to enable N. gonorrhoeae to colonize and invade a wide array of host tissues, both establishing and disseminating gonococcal infection.
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Affiliation(s)
- Emma Walker
- Te Huataki Waiora, School of Health, University of Waikato, Hamilton, New Zealand
| | - Stacy van Niekerk
- Te Huataki Waiora, School of Health, University of Waikato, Hamilton, New Zealand
| | - Kyrin Hanning
- Te Huataki Waiora, School of Health, University of Waikato, Hamilton, New Zealand
| | - William Kelton
- Te Huataki Waiora, School of Health, University of Waikato, Hamilton, New Zealand,Te Aka Mātuatua School of Science, University of Waikato, Hamilton, New Zealand
| | - Joanna Hicks
- Te Huataki Waiora, School of Health, University of Waikato, Hamilton, New Zealand,*Correspondence: Joanna Hicks,
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Prasad SK, Bhat S, Shashank D, C R A, R S, Rachtanapun P, Devegowda D, Santhekadur PK, Sommano SR. Bacteria-Mediated Oncogenesis and the Underlying Molecular Intricacies: What We Know So Far. Front Oncol 2022; 12:836004. [PMID: 35480118 PMCID: PMC9036991 DOI: 10.3389/fonc.2022.836004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 02/22/2022] [Indexed: 01/10/2023] Open
Abstract
Cancers are known to have multifactorial etiology. Certain bacteria and viruses are proven carcinogens. Lately, there has been in-depth research investigating carcinogenic capabilities of some bacteria. Reports indicate that chronic inflammation and harmful bacterial metabolites to be strong promoters of neoplasticity. Helicobacter pylori-induced gastric adenocarcinoma is the best illustration of the chronic inflammation paradigm of oncogenesis. Chronic inflammation, which produces excessive reactive oxygen species (ROS) is hypothesized to cause cancerous cell proliferation. Other possible bacteria-dependent mechanisms and virulence factors have also been suspected of playing a vital role in the bacteria-induced-cancer(s). Numerous attempts have been made to explore and establish the possible relationship between the two. With the growing concerns on anti-microbial resistance and over-dependence of mankind on antibiotics to treat bacterial infections, it must be deemed critical to understand and identify carcinogenic bacteria, to establish their role in causing cancer.
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Affiliation(s)
- Shashanka K Prasad
- Department of Biotechnology and Bioinformatics, Faculty of Life Sciences, Jagadguru Sri Shivarathreeshwara (JSS) Academy of Higher Education and Research (JSSAHER), Mysuru, India
| | - Smitha Bhat
- Department of Biotechnology and Bioinformatics, Faculty of Life Sciences, Jagadguru Sri Shivarathreeshwara (JSS) Academy of Higher Education and Research (JSSAHER), Mysuru, India
| | - Dharini Shashank
- Department of General Surgery, Adichunchanagiri Institute of Medical Sciences, Mandya, India
| | - Akshatha C R
- Department of Medical Oncology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
| | - Sindhu R
- Department of Microbiology, Faculty of Life Sciences, Jagadguru Sri Shivarathreeshwara (JSS) Academy of Higher Education and Research (JSSAHER), Mysuru, India
| | - Pornchai Rachtanapun
- School of Agro-Industry, Faculty of Agro-Industry, Chiang Mai University, Chiang Mai, Thailand.,Cluster of Agro Bio-Circular-Green Industry (Agro BCG), Chiang Mai University, Chiang Mai, Thailand
| | - Devananda Devegowda
- Centre of Excellence in Molecular Biology and Regenerative Medicine (CEMR), Department of Biochemistry, JSS Medical College, JSS Academy of Higher Education and Research (JSSAHER), Mysuru, India
| | - Prasanna K Santhekadur
- Centre of Excellence in Molecular Biology and Regenerative Medicine (CEMR), Department of Biochemistry, JSS Medical College, JSS Academy of Higher Education and Research (JSSAHER), Mysuru, India
| | - Sarana Rose Sommano
- Cluster of Agro Bio-Circular-Green Industry (Agro BCG), Chiang Mai University, Chiang Mai, Thailand.,Department of Plant and Soil Sciences, Faculty of Agriculture, Chiang Mai University, Chiang Mai, Thailand
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Sharma A, Yadav SP, Sarma D, Mukhopadhaya A. Modulation of host cellular responses by gram-negative bacterial porins. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2021; 128:35-77. [PMID: 35034723 DOI: 10.1016/bs.apcsb.2021.09.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The outer membrane of a gram-negative bacteria encapsulates the plasma membrane thereby protecting it from the harsh external environment. This membrane acts as a sieving barrier due to the presence of special membrane-spanning proteins called "porins." These porins are β-barrel channel proteins that allow the passive transport of hydrophilic molecules and are impermeable to large and charged molecules. Many porins form trimers in the outer membrane. They are abundantly present on the bacterial surface and therefore play various significant roles in the host-bacteria interactions. These include the roles of porins in the adhesion and virulence mechanisms necessary for the pathogenesis, along with providing resistance to the bacteria against the antimicrobial substances. They also act as the receptors for phage and complement proteins and are involved in modulating the host cellular responses. In addition, the potential use of porins as adjuvants, vaccine candidates, therapeutic targets, and biomarkers is now being exploited. In this review, we focus briefly on the structure of the porins along with their important functions and roles in the host-bacteria interactions.
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Affiliation(s)
- Arpita Sharma
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India
| | - Shashi Prakash Yadav
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India
| | - Dwipjyoti Sarma
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India
| | - Arunika Mukhopadhaya
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India.
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4
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Portnyagina O, Chistyulin D, Dyshlovoy S, Davidova V, Khomenko V, Shevchenko L, Novikova O. OmpF porin from Yersinia ruckeri as pathogenic factor: Surface antigenic sites and biological properties. Microb Pathog 2020; 150:104694. [PMID: 33359075 DOI: 10.1016/j.micpath.2020.104694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 12/06/2020] [Accepted: 12/07/2020] [Indexed: 10/22/2022]
Abstract
Bacterium Yersinia ruckeri as a pathogen induces causative agent of intestinal fish disease called enteric redmouth disease (ERM) is known. In this study, outer membrane OmpF porin from the Y. ruckeri (YrOmpF) has been identified as a pathogenic factor which affects host macrophage activation and life cycle of eukaryotic cells. Using synthetic peptides corresponding to the sequences of the outer loops of YrOmpF L1 loop of the porin is most involved in the structure of B epitopes on the surface of the microbial cell it was found. T epitopes of the isolated YrOmpF trimer not only by linear, but also by discontinuous determinants, which is due to the secondary structure of the protein are represented. It was shown that YrOmpF was twice more cytotoxic to THP-1 cells (human monocytes, cancer cells) in comparison with CHH-1 cells (Oncorhynchus keta cardiac muscle cell, non-cancer cells). It was found YrOmpF induce cell cycle S-phase arrest in both normal CHH-1 and cancer THP-1 cells. In the cancer cells observed effect was most pronounce. In addition, we have observed an induction of apoptosis in THP-1 cell line treated with YrOmpF for 48 h at IC50 (48.6 μg/ml). Significant cytotoxic effect of YrOmpF on primary mouse peritoneal macrophages been detected as well. Of note, co-incubation of macrophages with anti-YrOmpF antibodies could decrease the amount of lactate dehydrogenase, while the number of living cells significantly increased. YrOmpF stimulates the activity of the phagocytic bactericidal systems especially of the oxygen-independent subsystem it was found. Antibodies against YrOmpF decreased MPO release and CP synthesis by peritoneal macrophages and increased their viability.
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Affiliation(s)
- Olga Portnyagina
- G.B Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100 Let Vladivostoku, Vladivostok, 690022, Russian Federation; School of Natural Sciences, Far Eastern Federal University, 8 Sukhanova St., Vladivostok, 690090, Russian Federation.
| | - Dmitry Chistyulin
- G.B Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100 Let Vladivostoku, Vladivostok, 690022, Russian Federation
| | - Sergey Dyshlovoy
- School of Natural Sciences, Far Eastern Federal University, 8 Sukhanova St., Vladivostok, 690090, Russian Federation; University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Viktoriya Davidova
- G.B Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100 Let Vladivostoku, Vladivostok, 690022, Russian Federation
| | - Valentina Khomenko
- G.B Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100 Let Vladivostoku, Vladivostok, 690022, Russian Federation
| | - Ludmila Shevchenko
- G.B Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100 Let Vladivostoku, Vladivostok, 690022, Russian Federation
| | - Olga Novikova
- G.B Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100 Let Vladivostoku, Vladivostok, 690022, Russian Federation
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Lenz JD, Dillard JP. Pathogenesis of Neisseria gonorrhoeae and the Host Defense in Ascending Infections of Human Fallopian Tube. Front Immunol 2018; 9:2710. [PMID: 30524442 PMCID: PMC6258741 DOI: 10.3389/fimmu.2018.02710] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 11/02/2018] [Indexed: 12/28/2022] Open
Abstract
Neisseria gonorrhoeae is an obligate human pathogen that causes mucosal surface infections of male and female reproductive tracts, pharynx, rectum, and conjunctiva. Asymptomatic or unnoticed infections in the lower reproductive tract of women can lead to serious, long-term consequences if these infections ascend into the fallopian tube. The damage caused by gonococcal infection and the subsequent inflammatory response produce the condition known as pelvic inflammatory disease (PID). Infection can lead to tubal scarring, occlusion of the oviduct, and loss of critical ciliated cells. Consequences of the damage sustained on the fallopian tube epithelium include increased risk of ectopic pregnancy and tubal-factor infertility. Additionally, the resolution of infection can produce new adhesions between internal tissues, which can tear and reform, producing chronic pelvic pain. As a bacterium adapted to life in a human host, the gonococcus presents a challenge to the development of model systems for probing host-microbe interactions. Advances in small-animal models have yielded previously unattainable data on systemic immune responses, but the specificity of N. gonorrhoeae for many known (and unknown) host targets remains a constant hurdle. Infections of human volunteers are possible, though they present ethical and logistical challenges, and are necessarily limited to males due to the risk of severe complications in women. It is routine, however, that normal, healthy fallopian tubes are removed in the course of different gynecological surgeries (namely hysterectomy), making the very tissue most consequentially damaged during ascending gonococcal infection available for laboratory research. The study of fallopian tube organ cultures has allowed the opportunity to observe gonococcal biology and immune responses in a complex, multi-layered tissue from a natural host. Forty-five years since the first published example of human fallopian tube being infected ex vivo with N. gonorrhoeae, we review what modeling infections in human tissue explants has taught us about the gonococcus, what we have learned about the defenses mounted by the human host in the upper female reproductive tract, what other fields have taught us about ciliated and non-ciliated cell development, and ultimately offer suggestions regarding the next generation of model systems to help expand our ability to study gonococcal pathogenesis.
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Affiliation(s)
- Jonathan D Lenz
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, United States
| | - Joseph P Dillard
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, United States
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Anti-Inflammatory Effect of Feiyangchangweiyan Capsule on Rat Pelvic Inflammatory Disease through JNK/NF- κB Pathway. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2018; 2018:8476147. [PMID: 29681986 PMCID: PMC5851019 DOI: 10.1155/2018/8476147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/22/2018] [Accepted: 01/24/2018] [Indexed: 11/18/2022]
Abstract
Objectives In this study, we aimed to illustrate the preventive effect and possible mechanisms of Feiyangchangweiyan capsule (FYCWYC) on rat pelvic inflammatory disease (PID) model. Methods To construct the rat PID model, upper genital tract was infected by multipathogen, and then drugs were orally administered for 8 days. The histological examination, immunohistochemical analysis, and ELISA were carried out. Furthermore, Western blotting was used to analyze the expression of Akt, MAPKs, NF-κB p65, and IκB-α in uterus. Results As the results showed, infiltrations of neutrophils and lymphocytes in uterus were significantly suppressed, and IL-1β, IL-6, CXCL-1, and TNF-α were also reduced in a dose-dependent manner. We also found that FYCWYC inhibited apoptosis induced by infection. Furthermore, FYCWYC could block the infection-induced nuclear translocation of NF-κB. We found that FYCWYC treatment only decreased the phosphorylation of JNK induced by infection and had no effects on Akt and P38. Additional, the effects of SP600125, an inhibitor of phospho-JNK, were similar to the results of FYCWYC. Conclusions Taken together, our results demonstrated that FYCWYC had anti-inflammatory effect in pathogen-induced PID model, and the mechanism might be through inhibiting NF-κB nuclear translocation which is mediated by JNK.
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7
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The mechanism of Jurkat cells apoptosis induced by Aggregatibacter actinomycetemcomitans cytolethal distending toxin. Apoptosis 2017; 22:841-851. [DOI: 10.1007/s10495-017-1357-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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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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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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10
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Château A, Seifert HS. Neisseria gonorrhoeae survives within and modulates apoptosis and inflammatory cytokine production of human macrophages. Cell Microbiol 2016; 18:546-60. [PMID: 26426083 PMCID: PMC5240846 DOI: 10.1111/cmi.12529] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 09/17/2015] [Accepted: 09/28/2015] [Indexed: 12/28/2022]
Abstract
The human-adapted organism Neisseria gonorrhoeae is the causative agent of gonorrhoea, a sexually transmitted infection. It readily colonizes the genital, rectal and nasalpharyngeal mucosa during infection. While it is well established that N. gonorrhoeae recruits and modulates the functions of polymorphonuclear leukocytes during infection, how N. gonorrhoeae interacts with macrophages present in infected tissue is not fully defined. We studied the interactions of N. gonorrhoeae with two human monocytic cell lines, THP-1 and U937, and primary monocytes, all differentiated into macrophages. Most engulfed bacteria were killed in the phagolysosome, but a subset of bacteria was able to survive and replicate inside the macrophages suggesting that those cells may be an unexplored cellular reservoir for N. gonorrhoeae during infection. N. gonorrhoeae was able to modulate macrophage apoptosis: N. gonorrhoeae induced apoptosis in THP-1 cells whereas it inhibited induced apoptosis in U937 cells and primary human macrophages. Furthermore, N. gonorrhoeae induced expression of inflammatory cytokines in macrophages, suggesting a role for macrophages in recruiting polymorphonuclear leukocytes to the site of infection. These results indicate macrophages may serve as a significant replicative niche for N. gonorrhoeae and play an important role in gonorrheal pathogenesis.
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Affiliation(s)
- Alice Château
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - H. Steven Seifert
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
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11
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Liu GL, Parti RP, Dillon JAR. Suppression of ERK activation in urethral epithelial cells infected with Neisseria gonorrhoeae and its isogenic minD mutant contributes to anti-apoptosis. Microbes Infect 2014; 17:317-22. [PMID: 25554485 DOI: 10.1016/j.micinf.2014.12.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 12/15/2014] [Accepted: 12/17/2014] [Indexed: 10/24/2022]
Abstract
In gonococci-infected transduced human urethral epithelial cells (THUEC), the role of ERK, a mitogen-activated protein kinase (MAPK), in apoptosis is unknown. We observed lowering of ERK activation in THUEC following infection with anti-apoptosis-inducing Neisseria gonorrhoeae strain CH811. An isogenic cell division mutant of this strain, Ng CJSD1 (minD deficient), which is large and abnormally shaped, reduced ERK phosphorylation levels even more than its parental strain in THUEC. This led to higher anti-apoptosis in mutant-infected cells as compared to the parental strain-infected cells. Our results suggest that N. gonorrhoeae infection reduces ERK activation in THUEC contributing to anti-apoptosis.
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Affiliation(s)
- GuanQun L Liu
- Department of Biology, College of Arts and Science, University of Saskatchewan, W.P. Thompson Building 112 Science Place, Saskatoon, Saskatchewan, S7N5E2, Canada
| | - Rajinder P Parti
- Department of Biology, College of Arts and Science, University of Saskatchewan, W.P. Thompson Building 112 Science Place, Saskatoon, Saskatchewan, S7N5E2, Canada; Vaccine and Infectious Disease Organization-International Vaccine Center (VIDO-InterVac), University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, S7N5E3, Canada
| | - Jo-Anne R Dillon
- Department of Biology, College of Arts and Science, University of Saskatchewan, W.P. Thompson Building 112 Science Place, Saskatoon, Saskatchewan, S7N5E2, Canada; Vaccine and Infectious Disease Organization-International Vaccine Center (VIDO-InterVac), University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, S7N5E3, Canada; Department of Microbiology and Immunology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, S7N5E5, Canada.
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Crystallographic analysis of Neisseria meningitidis PorB extracellular loops potentially implicated in TLR2 recognition. J Struct Biol 2014; 185:440-7. [PMID: 24361688 PMCID: PMC3943661 DOI: 10.1016/j.jsb.2013.12.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 12/13/2013] [Accepted: 12/14/2013] [Indexed: 01/07/2023]
Abstract
Among all Neisseriae species, Neisseria meningitidis and Neisseria gonorrhoeae are the only human pathogens, causative agents of bacterial meningitis and gonorrhoea, respectively. PorB, a pan-Neisseriae trimeric porin that mediates diffusive transport of essential molecules across the bacterial outer membrane, is also known to activate host innate immunity via Toll-like receptor 2 (TLR2)-mediated signaling. The molecular mechanism of PorB binding to TLR2 is not known, but it has been hypothesized that electrostatic interactions contribute to ligand/receptor binding. Strain-specific sequence variability in the surface-exposed loops of PorB which are potentially implicated in TLR2 binding, may explain the difference in TLR2-mediated cell activation in vitro by PorB homologs from the commensal Neisseriae lactamica and the pathogen N. meningitidis. Here, we report a comparative structural analysis of PorB from N. meningitidis serogroup B strain 8765 (63% sequence homology with PorB from N. meningitidis serogroup W135) and a mutant in which amino acid substitutions in the extracellular loop 7 lead to significantly reduced TLR2-dependent activity in vitro. We observe that this mutation both alters the loop conformation and causes dramatic changes of electrostatic surface charge, both of which may affect TLR2 recognition and signaling.
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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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Infection with Anaplasma phagocytophilum activates the phosphatidylinositol 3-Kinase/Akt and NF-κB survival pathways in neutrophil granulocytes. Infect Immun 2012; 80:1615-23. [PMID: 22252875 DOI: 10.1128/iai.05219-11] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Anaplasma phagocytophilum, a Gram-negative, obligate intracellular bacterium infects primarily neutrophil granulocytes. Infection with A. phagocytophilum leads to inhibition of neutrophil apoptosis and consequently contributes to the longevity of the host cells. Previous studies demonstrated that the infection inhibits the executionary apoptotic machinery in neutrophils. However, little attempt has been made to explore which survival signals are modulated by the pathogen. The aim of the present study was to clarify whether the phosphatidylinositol 3-kinase (PI3K)/Akt and NF-κB signaling pathways, which are considered as important survival pathways in neutrophils, are involved in A. phagocytophilum-induced apoptosis delay. Our data show that infection of neutrophils with A. phagocytophilum activates the PI3K/Akt pathway and suggest that this pathway, which in turn maintains the expression of the antiapoptotic protein Mcl-1, contributes to the infection-induced apoptosis delay. In addition, the PI3K/Akt pathway is involved in the activation of NF-κB in A. phagocytophilum-infected neutrophils. Activation of NF-κB leads to the release of interleukin-8 (IL-8) from infected neutrophils, which, in an autocrine manner, delays neutrophil apoptosis. In addition, enhanced expression of the antiapoptotic protein cIAP2 was observed in A. phagocytophilum-infected neutrophils. Taken together, the data indicate that upstream of the apoptotic cascade, signaling via the PI3K/Akt pathway plays a major role for apoptosis delay in A. phagocytophilum-infected neutrophils.
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Massari P, Wetzler LM. Analysis of parameters associated with prevention of cellular apoptosis by pathogenic Neisseriae and purified porins. Methods Mol Biol 2012; 799:319-41. [PMID: 21993654 DOI: 10.1007/978-1-61779-346-2_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/19/2024]
Abstract
The process of cellular apoptosis is mediated by a number of microbial pathogens to modulate host defense mechanisms. Inhibition of apoptosis is thought to favor microbial survival, replication or immune evasion, while induction of apoptosis is likely to promote escape of the organisms from host cells. Several studies have reported that infection with Neisseria spp. can inhibit or reduce apoptotic cell death, thus allowing adaptation, intracellular replication, and immune evasion, events that are likely to spread infection. In this chapter, various techniques are described for direct measurement of host cell responses to infection with Neisseria meningitidis and to treatment with pure Neisseria porins, the major proteins found in the outer membrane of the pathogen.
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Affiliation(s)
- Paola Massari
- Department of Medicine, Evans BioMedical Research Center, Section of Infectious Diseases, Boston University School of Medicine, Boston, MA, USA.
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Vielfort K, Söderholm N, Weyler L, Vare D, Löfmark S, Aro H. Neisseria gonorrhoeae infection causes DNA damage and affects the expression of p21, p27, and p53 in non-tumor epithelial cells. J Cell Sci 2012; 126:339-47. [DOI: 10.1242/jcs.117721] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The constant shedding and renewal of epithelial cells maintain the protection of epithelial barriers. Interference with the processes of host cell-cycle regulation and barrier integrity permits the bacterial pathogen Neisseria gonorrhoeae to effectively colonize and invade epithelial cells. Here, we show that a gonococcal infection causes DNA damage in human non-tumor vaginal VK2/E6E7 cells with an increase of 700 DNA strand breaks per cell per hour as detected by an alkaline DNA unwinding assay. Infected cells exhibited elevated levels of DNA double-strand breaks, as indicated by a more than 50% increase in cells expressing DNA damage-response protein 53BP1-positive foci that co-localized with phosphorylated histone H2AX (γH2AX). Furthermore, infected cells abolished their expression of the tumor protein p53 and induced an increase in the expression of cyclin-dependent kinase inhibitors p21 and p27 to 2.6-fold and 4.2-fold of controls, respectively. As shown by live-cell microscopy, flow cytometry assays, and BrdU incorporation assays, gonococcal infection slowed the host cell-cycle progression mainly by impairing progression through the G2 phase. Our findings show new cellular players that are involved in the control of the human cell cycle during gonococcal infection and the potential of bacteria to cause cellular abnormalities.
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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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Dietrich M, Bartfeld S, Munke R, Lange C, Ogilvie LA, Friedrich A, Meyer TF. Activation of NF-κB by Neisseria gonorrhoeae is associated with microcolony formation and type IV pilus retraction. Cell Microbiol 2011; 13:1168-82. [PMID: 21615661 DOI: 10.1111/j.1462-5822.2011.01607.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The early stage of infection with Neisseria gonorrhoeae (Ngo), the causative agent of gonorrhoea, is marked by type IV pilus (Tfp)-mediated attachment and the formation of bacterial microcolonies on epithelial cells. Retraction of the Ngo Tfp generates substantial force on its substrate which can elicit host cell signalling. Here, we observed that this retraction force could also activate nuclear factor (NF)-κB, the central signalling cascade of innate immunity. Using a p65-GFP-expressing epithelial cell line, we show that piliated Ngo induce asynchronous NF-κB activation in infected cells, which is temporally associated with the formation of gonococcal microcolonies. A mutant lacking PilT, an ATPase necessary for Tfp retraction, induced markedly reduced NF-κB activation. This was accompanied by decreased NF-κB target gene transcription and cytokine release. The impaired ability of the pilT mutant to activate NF-κB was compensated by applying mechanical shear stress to the infected host cells, indicating that the mechanical forces generated by retractile pili are involved in the retraction-dependent activation of NF-κB elicited by gonococcal microcolonies. Thus, our work provides evidence for an intriguing relationship between microcolony growth, pilus retraction and host cell signalling, with likely implications with regard to the course of symptomatic versus asymptomatic gonococcal infections.
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Affiliation(s)
- Manuela Dietrich
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
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20
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NleH effectors interact with Bax inhibitor-1 to block apoptosis during enteropathogenic Escherichia coli infection. Proc Natl Acad Sci U S A 2010; 107:3129-34. [PMID: 20133763 DOI: 10.1073/pnas.0911609106] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The human pathogens enteropathogenic (EPEC) and enterohemorrhagic Escherichia coli and the related mouse pathogen Citrobacter rodentium subvert a variety of host cell signaling pathways via their plethora of type III secreted effectors, including triggering of an early apoptotic response. EPEC-infected cells do not develop late apoptotic symptoms, however. In this study we demonstrate that the NleH family effectors, homologs of the Shigella effector kinase OspG, blocks apoptosis. During EPEC infection, NleH effectors inhibit elevation of cytosolic Ca(2+) concentrations, nuclear condensation, caspase-3 activation, and membrane blebbing and promote cell survival. NleH1 alone is sufficient to prevent procaspase-3 cleavage induced by the proapoptotic compounds staurosporine, brefeldin A, and tunicamycin. Using C. rodentium, we found that NleH inhibits procaspase-3 cleavage at the bacterial attachment sites in vivo. A yeast two-hybrid screen identified the endoplasmic reticulum six-transmembrane protein Bax inhibitor-1 (BI-1) as an NleH-interacting partner. We mapped the NleH-binding site to the N-terminal 40 amino acids of BI-1. Knockdown of BI-1 resulted in the loss of NleH's antiapoptotic activity. These results indicate that NleH effectors are inhibitors of apoptosis that may act through BI-1 to carry out their cytoprotective function.
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Meningococcal porin PorB prevents cellular apoptosis in a toll-like receptor 2- and NF-kappaB-independent manner. Infect Immun 2009; 78:994-1003. [PMID: 20028813 DOI: 10.1128/iai.00156-09] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Meningococcal porin PorB is an inhibitor of apoptosis induced via the intrinsic pathway in various cell types. This effect is attributed to prevention of mitochondrial depolarization and of subsequent release of proapoptotic mitochondrial factors. To determine whether apoptosis is globally inhibited by PorB, we compared the intrinsic and extrinsic pathways in HeLa cells. Interestingly, PorB does not prevent extrinsic apoptosis induced by tumor necrosis factor alpha plus cycloheximide, suggesting a unique mitochondrial pathway specificity. Several intracellular factors regulated by NF-kappaB, including members of the Bcl-2 family and of the inhibitor of apoptosis (IAP) family, play major roles in controlling apoptosis, and some of them are thought to contribute to the antiapoptotic effect of the gonococcal porin, PIB. However, most of the members of the Bcl-2 family and the IAP family are not induced by meningococcal PorB in HeLa cells, with the exception of Bfl-1/A1. Interestingly, PorB does not induce NF-kappaB activation in HeLa cells, likely due to a lack of Toll-like receptor 2 (TLR2) expression in these cells. Bfl-1/A1 expression is also regulated by CBF1, a nuclear component of the Notch signaling pathway, independent of NF-kappaB activation. Since HeLa cells are protected by PorB from intrinsic apoptosis events, regardless of TLR2 and NF-kappaB expression, the possibility of a contribution of alternative signaling pathways to this effect cannot be excluded. In this paper, we describe an initial dissection of the cascade of cellular events involved in the antiapoptotic effect of PorB in the absence of TLR2.
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Neisseria gonorrhoeae infection protects human endocervical epithelial cells from apoptosis via expression of host antiapoptotic proteins. Infect Immun 2009; 77:3602-10. [PMID: 19546192 DOI: 10.1128/iai.01366-08] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Several microbial pathogens can modulate the host apoptotic response to infection, which may contribute to immune evasion. Various studies have reported that infection with the sexually transmitted disease pathogen Neisseria gonorrhoeae can either inhibit or induce apoptosis. N. gonorrhoeae infection initiates at the mucosal epithelium, and in women, cells from the ectocervix and endocervix are among the first host cells encountered by this pathogen. In this study, we defined the antiapoptotic effect of N. gonorrhoeae infection in human endocervical epithelial cells (End/E6E7 cells). We first established that N. gonorrhoeae strain FA1090B failed to induce cell death in End/E6E7 cells. Subsequently, we demonstrated that stimulation with N. gonorrhoeae protected these cells from staurosporine (STS)-induced apoptosis. Importantly, only End/E6E7 cells incubated with live bacteria and in direct association with N. gonorrhoeae were protected from STS-induced apoptosis, while heat-killed and antibiotic-killed bacteria failed to induce protection. Stimulation of End/E6E7 cells with live N. gonorrhoeae induced NF-kappaB activation and resulted in increased gene expression of the NF-kappaB-regulated antiapoptotic genes bfl-1, cIAP-2, and c-FLIP. Furthermore, cIAP-2 protein levels also increased in End/E6E7 cells incubated with gonococci. Collectively, our results indicate that the antiapoptotic effect of N. gonorrhoeae in human endocervical epithelial cells results from live infection via expression of host antiapoptotic proteins. Securing an intracellular niche through the inhibition of apoptosis may be an important mechanism utilized by N. gonorrhoeae for microbial survival and immune evasion in cervical epithelial cells.
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Duncan JA, Gao X, Huang MTH, O'Connor BP, Thomas CE, Willingham SB, Bergstralh DT, Jarvis GA, Sparling PF, Ting JPY. Neisseria gonorrhoeae activates the proteinase cathepsin B to mediate the signaling activities of the NLRP3 and ASC-containing inflammasome. THE JOURNAL OF IMMUNOLOGY 2009; 182:6460-9. [PMID: 19414800 DOI: 10.4049/jimmunol.0802696] [Citation(s) in RCA: 205] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Neisseria gonorrhoeae is a common sexually transmitted pathogen that significantly impacts female fertility, neonatal health, and transmission of HIV worldwide. N. gonorrhoeae usually causes localized inflammation of the urethra and cervix by inducing production of IL-1beta and other inflammatory cytokines. Several NLR (nucleotide-binding domain, leucine-rich repeat) proteins are implicated in the formation of pro-IL-1beta-processing complexes called inflammasomes in response to pathogens. We demonstrate that NLRP3 (cryopyrin, NALP3) is the primary NLR required for IL-1beta/IL-18 secretion in response to N. gonorrhoeae in monocytes. We also show that N. gonorrhoeae infection promotes NLRP3-dependent monocytic cell death via pyronecrosis, a recently described pathway with morphological features of necrosis, including release of the strong inflammatory mediator HMBG1. Additionally, N. gonorrhoeae activates the cysteine protease cathepsin B as measured by the breakdown of a cathepsin B substrate. Inhibition of cathepsin B shows that this protease is an apical controlling step in the downstream activities of NLRP3 including IL-1beta production, pyronecrosis, and HMGB1 release. Nonpathogenic Neisseria strains (Neisseria cinerea and Neisseria flavescens) do not activate NLRP3 as robustly as N. gonorrhoeae. Conditioned medium from N. gonorrhoeae contains factors capable of initiating the NLRP3-mediated signaling events. Isolated N. gonorrhoeae lipooligosaccharide, a known virulence factor from this bacterium that is elaborated from the bacterium in the form of outer membrane blebs, activates both NLRP3-induced IL-1beta secretion and pyronecrosis. Our findings indicate that activation of NLRP3-mediated inflammatory response pathways is an important venue associated with host response and pathogenesis of N. gonorrhoeae.
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Affiliation(s)
- Joseph A Duncan
- Department of Medicine, Division of Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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24
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Koziel J, Maciag-Gudowska A, Mikolajczyk T, Bzowska M, Sturdevant DE, Whitney AR, Shaw LN, DeLeo FR, Potempa J. Phagocytosis of Staphylococcus aureus by macrophages exerts cytoprotective effects manifested by the upregulation of antiapoptotic factors. PLoS One 2009; 4:e5210. [PMID: 19381294 PMCID: PMC2668171 DOI: 10.1371/journal.pone.0005210] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Accepted: 03/18/2009] [Indexed: 12/26/2022] Open
Abstract
It is becoming increasingly apparent that Staphylococcus aureus are able to survive engulfment by macrophages, and that the intracellular environment of these host cells, which is essential to innate host defenses against invading microorganisms, may in fact provide a refuge for staphylococcal survival and dissemination. Based on this, we postulated that S. aureus might induce cytoprotective mechanisms by changing gene expression profiles inside macrophages similar to obligate intracellular pathogens, such as Mycobacterium tuberculosis. To validate our hypothesis we first ascertained whether S. aureus infection could affect programmed cell death in human (hMDMs) and mouse (RAW 264.7) macrophages and, specifically, protect these cells against apoptosis. Our findings indicate that S. aureus-infected macrophages are more resistant to staurosporine-induced cell death than control cells, an effect partly mediated via the inhibition of cytochrome c release from mitochondria. Furthermore, transcriptome analysis of human monocyte-derived macrophages during S. aureus infection revealed a significant increase in the expression of antiapoptotic genes. This was confirmed by quantitative RT-PCR analysis of selected genes involved in mitochondria-dependent cell death, clearly showing overexpression of BCL2 and MCL1. Cumulatively, the results of our experiments argue that S. aureus is able to induce a cytoprotective effect in macrophages derived from different mammal species, which can prevent host cell elimination, and thus allow intracellular bacterial survival. Ultimately, it is our contention that this process may contribute to the systemic dissemination of S. aureus infection.
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Affiliation(s)
- Joanna Koziel
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
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25
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Phenotypic and genotypic analyses of Neisseria gonorrhoeae isolates that express frequently recovered PorB PIA variable region types suggest that certain P1a porin sequences confer a selective advantage for urogenital tract infection. Infect Immun 2008; 76:3700-9. [PMID: 18541655 DOI: 10.1128/iai.00265-08] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Typing of the porB variable region (VR) is an epidemiological tool that classifies gonococcal strains based on sequence differences in regions of the porB gene that encode surface-exposed loops. The frequent isolation of certain porB VR types suggests that some porin sequences confer a selective advantage during infection and/or transmission. Alternatively, certain porin types may be markers of strains that are successful due to factors unrelated to porin. In support of the first hypothesis, here we show urogenital tract isolates representing the most common PIA VR types identified in an urban clinic in Baltimore, MD, over a 10-year period belonged to several different clonal types, as determined by pulsed-field gel electrophoresis (PFGE). Serum resistance, which was confirmed by factor H and C4b-binding protein binding studies, was more often associated with gonococcal the most common VR types. In contrast, three porin-independent phenotypes, namely, lactoferrin utilization, beta-lactamase production, and multiple transferable resistance (Mtr), were segregated with the PFGE cluster and not with the VR type. Data combined with another PIA strain collection showed a strong correlation between serum resistance and the most common VR types. A comparison of VR typing hybridization patterns and nucleotide sequences of 12 porB1a genes suggests that certain porin loop 1, 3, 6, and/or 7 sequences may play a role in the serum resistance phenotype. We conclude that some PorB PIA sequences confer a survival or transmission advantage in the urogenital tract, perhaps via increased resistance to complement-mediated killing. The capacity of some porin types to evade a porin-specific adaptive immune response must also be considered.
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Extracellular signal-regulated kinase activation by Neisseria gonorrhoeae downregulates epithelial cell proapoptotic proteins Bad and Bim. Infect Immun 2008; 76:2715-21. [PMID: 18391004 DOI: 10.1128/iai.00153-08] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Neisseria gonorrhoeae expressing type IV pili (Tfp) activates extracellular signal-regulated kinase (ERK) and induces a cytoprotective state in the epithelial cell in a manner that is enhanced by pilT. As the ERK signaling pathway is well-known for its role in cytoprotection and cell survival, we tested the hypothesis that ERK is involved in producing this cytoprotective effect. Inhibiting ERK activation prior to infection attenuated the ability of these bacteria to induce cytoprotection. Activated ERK specifically targeted two proapoptotic Bcl-2 homology domain 3 (BH3)-only proteins, Bim and Bad, for downregulation at the protein level. Bim downregulation occurred through the proteasome. ERK, in addition, inactivated Bad by triggering its phosphorylation at Ser112. Finally, reducing the level of either Bad or Bim alone by small interfering RNA was sufficient to protect uninfected cells from staurosporine-induced apoptosis. We conclude that Tfp-induced cytoprotection is due in part to ERK-dependent modification and/or downregulation of proapoptotic proteins Bad and Bim.
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Faherty CS, Maurelli AT. Staying alive: bacterial inhibition of apoptosis during infection. Trends Microbiol 2008; 16:173-80. [PMID: 18353648 PMCID: PMC2746948 DOI: 10.1016/j.tim.2008.02.001] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2008] [Accepted: 02/01/2008] [Indexed: 01/14/2023]
Abstract
The ability of bacterial pathogens to inhibit apoptosis in eukaryotic cells during infection is an emerging theme in the study of bacterial pathogenesis. Prevention of apoptosis provides a survival advantage because it enables the bacteria to replicate inside host cells. Bacterial pathogens have evolved several ways to prevent apoptosis by protecting the mitochondria and preventing cytochrome c release, by activating cell survival pathways, or by preventing caspase activation. This review summarizes the most recent work on bacterial anti-apoptotic strategies and suggests new research that is necessary to advance the field.
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Affiliation(s)
- Christina S Faherty
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814-4799, USA
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Clark CS, Maurelli AT. Shigella flexneri inhibits staurosporine-induced apoptosis in epithelial cells. Infect Immun 2007; 75:2531-9. [PMID: 17339354 PMCID: PMC1865761 DOI: 10.1128/iai.01866-06] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Revised: 12/26/2006] [Accepted: 02/21/2007] [Indexed: 01/19/2023] Open
Abstract
Shigella flexneri is a facultative intracellular organism that causes bacillary dysentery. The Shigella IpaB protein activates caspase 1 in macrophages, which eventually leads to apoptosis. In contrast, epithelial cells infected with Shigella undergo a stress response but do not die. Therefore, the objective of this study was to determine if Shigella has the ability to inhibit apoptosis in epithelial cells. A modified gentamicin protection assay was used to investigate if HeLa cells infected with S. flexneri are able to resist the induction of apoptosis following treatment with 4 microM of staurosporine. Nuclear staining and immunofluorescence revealed that infected cells remained healthy while uninfected cells appeared apoptotic. Only uninfected cells had detectable levels of activated caspase 3 upon immunofluorescence, and this was verified by Western blot analysis. Despite interfering with caspase 3 activation, Shigella-infected cells treated with staurosporine did have cytochrome c release and caspase 9 activation, indicating that Shigella protects epithelial cells from apoptosis by inhibiting caspase 3 activation. Analysis of S. flexneri mutants showed that invasion and a functional type III secretion system were required to block apoptosis. In addition, a mutant with a deletion in mxiE, which encodes a transcriptional activator for genes induced intracellularly, failed to inhibit apoptosis. Therefore, protection of epithelial cells from apoptosis by S. flexneri is regulated by one or more of the bacterial genes under the control of mxiE. We believe that S. flexneri, like other pathogens, inhibits apoptosis in epithelial cells but causes apoptosis in macrophages to ensure survival inside the host.
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Affiliation(s)
- Christina S Clark
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814-4799, USA
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Simons MP, Nauseef WM, Griffith TS, Apicella MA. Neisseria gonorrhoeae delays the onset of apoptosis in polymorphonuclear leukocytes. Cell Microbiol 2006; 8:1780-90. [PMID: 16803582 DOI: 10.1111/j.1462-5822.2006.00748.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Neisseria gonorrhoeae (gonococcus) infection results in recruitment of polymorphonuclear leukocytes (PMNs) to the urethral lumen. Recent work from our laboratory demonstrated that N. gonorrhoeae resists killing and replicates within PMNs. In this study, we examined the effect of gonococci on PMN viability. Using both transmission electron microscopy and light microscopy, we observed nuclear condensation after 6 h in PMNs that were resting or challenged with opsonized zymosan particles (OPZ). In contrast, N. gonorrhoeae delayed nuclear condensation in PMNs for 12 h (13% apoptotic PMNs vs. 90% for resting and 94% for OPZ-stimulated PMNs). Additionally, DNA fragmentation was reduced in PMNs challenged with gonococci for 12 h (28% apoptosis vs. 52% for resting and 98% for OPZ-stimulated PMNs). However, 74% of PMNs challenged with gonococci had condensed nuclei and 67% had fragmented DNA after 24 h. Caspase activity (total caspase, caspase-3/7, caspase-9) was reduced at 4 h and mitochondrial integrity was preserved at 2 h in PMNs challenged with N. gonorrhoeae. Quantitative reverse transcription polymerase chain reaction demonstrated that mRNA levels of X-IAP and cIAP-2 remained high after challenge with gonococci, but were downregulated in OPZ-stimulated PMNs. Collectively, these findings demonstrate that N. gonorrhoeae delayed apoptosis in PMNs, perhaps as a strategy to allow intracellular replication.
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Affiliation(s)
- Mark P Simons
- Department of Microbiology, Inflammation Program, University of Iowa, Iowa City, Iowa 52242, USA
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Morales P, Reyes P, Vargas M, Rios M, Imarai M, Cardenas H, Croxatto H, Orihuela P, Vargas R, Fuhrer J, Heckels JE, Christodoulides M, Velasquez L. Infection of human fallopian tube epithelial cells with Neisseria gonorrhoeae protects cells from tumor necrosis factor alpha-induced apoptosis. Infect Immun 2006; 74:3643-50. [PMID: 16714596 PMCID: PMC1479248 DOI: 10.1128/iai.00012-06] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Following infection with Neisseria gonorrhoeae, bacteria may ascend into the Fallopian tubes (FT) and induce salpingitis, a major cause of infertility. In the FT, interactions between mucosal epithelial cells and gonococci are pivotal events in the pathogen's infection cycle and the inflammatory response. In the current study, primary FT epithelial cells were infected in vitro with different multiplicities of infection (MOI) of Pil+ Opa+ gonococci. Bacteria showed a dose-dependent association with cells and induced the secretion of tumor necrosis factor alpha (TNF-alpha). A significant finding was that gonococcal infection (MOI = 1) induced apoptosis in approximately 30% of cells, whereas increasing numbers of bacteria (MOI = 10 to 100) did not induce apoptosis. Apoptosis was observed in only 11% of cells with associated bacteria, whereas >84% of cells with no adherent bacteria were apoptotic. TNF-alpha was a key contributor to apoptosis, since (i) culture supernatants from cells infected with gonococci (MOI = 1) induced apoptosis in naïve cultures, suggesting that a soluble factor was responsible; (ii) gonococcal infection-induced apoptosis was inhibited with anti-TNF-alpha antibodies; and (iii) the addition of exogenous TNF-alpha induced apoptosis, which was inhibited by the presence of increasing numbers of bacteria (MOI = 10 to 100). These data suggest that TNF-alpha-mediated apoptosis of FT epithelial cells is likely a primary host defense mechanism to prevent pathogen colonization. However, epithelial cell-associated gonococci have evolved a mechanism to protect the cells from undergoing TNF-alpha-mediated apoptosis, and this modulation of the host innate response may contribute to establishment of infection. Understanding the antiapoptotic mechanisms used by Neisseria gonorrhoeae will inform the pathogenesis of salpingitis and could suggest new intervention strategies for prevention and treatment of the disease.
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Affiliation(s)
- Priscilla Morales
- Laboratorio de Inmunología de la Reproducción, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
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Zhang T, Lu H, Shang X, Tian Y, Zheng C, Wang S, Cheng H, Zhou R. Nicotine prevents the apoptosis induced by menadione in human lung cancer cells. Biochem Biophys Res Commun 2006; 342:928-34. [PMID: 16598845 DOI: 10.1016/j.bbrc.2006.02.047] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Approximately 50% of long-term cigarette smokers die prematurely from the adverse effects of smoking, including on lung cancer and other illnesses. Nicotine is a main component in tobacco and has been implicated as a potential factor in the pathogenesis of human lung cancer. However, the mechanism of nicotine action in the development of lung cancer remains largely unknown. In the present study, we designed a nicotine-apoptosis system, by pre-treatment of nicotine making lung cancer cell A549 to be in a physiological nicotine environment, and observed that nicotine promoted cell proliferation and prevented the menadione-induced apoptosis, and exerts its role of anti-apoptosis by shift of apoptotic stage induced by menadione from late apoptotic stage to early apoptotic stage, in which NF-kappaB was up-regulated. Interference analysis of NF-kappaB in A549 cells showed that knock down of NF-kappaB resulted in apoptosis promotion and counteracted the protective effect of nicotine. The findings suggest that nicotine has potential effect in lung cancer genesis, especially in patients with undetectable early tumor development and development of specific NF-kappaB inhibitors would represent a potentially exciting new pharmacotherapy for tobacco-related lung cancer.
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Affiliation(s)
- Tao Zhang
- Department of Genetics and Center for Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China
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Abstract
In response to invasion by microbial pathogens, host defense mechanisms get activated by both the innate and adaptive arms of the immune responses. TNF (tumor necrosis factor) is a potent proinflammatory cytokine expressed by activated macrophages and lymphocytes that induces diverse cellular responses that can vary from apoptosis to the expression of genes involved in both early inflammatory and acquired immune responses. A wide spectrum of microbes has acquired elegant mechanisms to overcome or deflect the host responses mediated by TNF. For example, modulatory proteins encoded by multiple families of viruses can block TNF and TNF-mediated responses at multiple levels, such as the inhibition of the TNF ligand or its receptors, or by modulating key transduction molecules of the TNF signaling pathway. Bacteria, on the other hand, tend to modify TNF-mediated responses specifically by regulating components of the TNF signaling pathway. Investigation of these diverse strategies employed by viral and bacterial pathogens has significantly advanced our understanding of both host TNF responses and microbial pathogenesis. This review summarizes the diverse microbial strategies to regulate TNF and how such insights into TNF modulation could benefit the treatment of inflammatory or autoimmune diseases.
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Brettin T, Altherr MR, Du Y, Mason RM, Friedrich A, Potter L, Langford C, Keller TJ, Jens J, Howie H, Weyand NJ, Clary S, Prichard K, Wachocki S, Sodergren E, Dillard JP, Weinstock G, So M, Arvidson CG. Expression capable library for studies of Neisseria gonorrhoeae, version 1.0. BMC Microbiol 2005; 5:50. [PMID: 16137322 PMCID: PMC1236931 DOI: 10.1186/1471-2180-5-50] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2005] [Accepted: 09/01/2005] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND The sexually transmitted disease, gonorrhea, is a serious health problem in developed as well as in developing countries, for which treatment continues to be a challenge. The recent completion of the genome sequence of the causative agent, Neisseria gonorrhoeae, opens up an entirely new set of approaches for studying this organism and the diseases it causes. Here, we describe the initial phases of the construction of an expression-capable clone set representing the protein-coding ORFs of the gonococcal genome using a recombination-based cloning system. RESULTS The clone set thus far includes 1672 of the 2250 predicted ORFs of the N. gonorrhoeae genome, of which 1393 (83%) are sequence-validated. Included in this set are 48 of the 61 ORFs of the gonococcal genetic island of strain MS11, not present in the sequenced genome of strain FA1090. L-arabinose-inducible glutathione-S-transferase (GST)-fusions were constructed from random clones and each was shown to express a fusion protein of the predicted size following induction, demonstrating the use of the recombination cloning system. PCR amplicons of each ORF used in the cloning reactions were spotted onto glass slides to produce DNA microarrays representing 2035 genes of the gonococcal genome. Pilot experiments indicate that these arrays are suitable for the analysis of global gene expression in gonococci. CONCLUSION This archived set of Gateway entry clones will facilitate high-throughput genomic and proteomic studies of gonococcal genes using a variety of expression and analysis systems. In addition, the DNA arrays produced will allow us to generate gene expression profiles of gonococci grown in a wide variety of conditions. Together, the resources produced in this work will facilitate experiments to dissect the molecular mechanisms of gonococcal pathogenesis on a global scale, and ultimately lead to the determination of the functions of unknown genes in the genome.
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Affiliation(s)
- Thomas Brettin
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Michael R Altherr
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Ying Du
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824-4320, USA
| | - Roxie M Mason
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824-4320, USA
| | - Alexandra Friedrich
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97201-3098, USA
| | - Laura Potter
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97201-3098, USA
- Leicester Warwick Medical School, University of Warwick, Coventry, UK
| | - Chris Langford
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97201-3098, USA
| | - Thomas J Keller
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97201-3098, USA
| | - Jason Jens
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824-4320, USA
| | - Heather Howie
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97201-3098, USA
| | - Nathan J Weyand
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97201-3098, USA
| | - Susan Clary
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97201-3098, USA
| | - Kimberly Prichard
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Susi Wachocki
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Erica Sodergren
- Human Genome Sequencing Center, Baylor College of Medicine, Houston TX 77030, USA
| | - Joseph P Dillard
- Department of Medical Microbiology and Immunology, University of Wisconsin Medical School, Madison, WI 53706, USA
| | - George Weinstock
- Human Genome Sequencing Center, Baylor College of Medicine, Houston TX 77030, USA
| | - Magdalene So
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97201-3098, USA
| | - Cindy Grove Arvidson
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824-4320, USA
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Häcker G, Kirschnek S, Fischer SF. Apoptosis in infectious disease: how bacteria interfere with the apoptotic apparatus. Med Microbiol Immunol 2005; 195:11-9. [PMID: 16086183 DOI: 10.1007/s00430-005-0239-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2005] [Indexed: 10/25/2022]
Abstract
Cell death by apoptosis is a common response of a human cell to many extrinsic stimuli. A cell's sensitivity to apoptotic triggers is affected by its activation and differentiation status. Bacteria are recognised by cellular receptors and elicit a multitude of signal transduction events that can, among other effects, alter the cell's response towards apoptotic stimuli. Many different bacteria and bacterial products have been recognised as agents that can act in this way and either induce or inhibit cell death. Besides these common and, as we argue, indirect activities, chlamydiae have been described to have a more specific capacity. These specialists of intracellular life can directly attack the host cell's apoptotic pathway. Here, we will attempt to structure the field of bacterial inhibition of apoptosis and discuss recent advancements in our knowledge of how chlamydiae interfere with the host cell's capacity to undergo apoptosis.
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Affiliation(s)
- Georg Häcker
- Institute for Medical Microbiology, Immunology and Hygiene, Technical University Munich, Trogerstr. 9, 81675 Munich, Germany.
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Snyder LAS, Davies JK, Ryan CS, Saunders NJ. Comparative overview of the genomic and genetic differences between the pathogenic Neisseria strains and species. Plasmid 2005; 54:191-218. [PMID: 16024078 DOI: 10.1016/j.plasmid.2005.04.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2005] [Revised: 04/18/2005] [Accepted: 04/21/2005] [Indexed: 01/19/2023]
Abstract
The availability of complete genome sequences from multiple pathogenic Neisseria strains and species has enabled a comprehensive survey of the genomic and genetic differences occurring within these species. In this review, we describe the chromosomal rearrangements that have occurred, and the genomic islands and prophages that have been identified in the various genomes. We also describe instances where specific genes are present or absent, other instances where specific genes have been inactivated, and situations where there is variation in the version of a gene that is present. We also provide an overview of mosaic genes present in these genomes, and describe the variation systems that allow the expression of particular genes to be switched ON or OFF. We have also described the presence and location of mobile non-coding elements in the various genomes. Finally, we have reviewed the incidence and properties of various extra-chromosomal elements found within these species. The overall impression is one of genomic variability and instability, resulting in increased functional flexibility within these species.
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Affiliation(s)
- Lori A S Snyder
- Bacterial Pathogenesis and Functional Genomics Group, Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
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Greiner LL, Edwards JL, Shao J, Rabinak C, Entz D, Apicella MA. Biofilm Formation by Neisseria gonorrhoeae. Infect Immun 2005; 73:1964-70. [PMID: 15784536 PMCID: PMC1087446 DOI: 10.1128/iai.73.4.1964-1970.2005] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Studies were performed in continuous-flow chambers to determine whether Neisseria gonorrhoeae could form a biofilm. Under these growth conditions, N. gonorrhoeae formed a biofilm with or without the addition of 10 microM sodium nitrite to the perfusion medium. Microscopic analysis of a 4-day growth of N. gonorrhoeae strain 1291 revealed evidence of a biofilm with organisms embedded in matrix, which was interlaced with water channels. N. gonorrhoeae strains MS11 and FA1090 were found to also form biofilms under the same growth conditions. Cryofield emission scanning electron microscopy and transmission electron microscopy confirmed that organisms were embedded in a continuous matrix with membranous structures spanning the biofilm. These studies also demonstrated that N. gonorrhoeae has the capability to form a matrix in the presence and absence of CMP-N-acetylneuraminic acid (CMP-Neu5Ac). Studies with monoclonal antibody 6B4 and the lectins soy bean agglutinin and Maackia amurensis indicated that the predominate terminal sugars in the biofilm matrix formed a lactosamine when the biofilm was grown in the absence of CMP-Neu5Ac and sialyllactosamine in the presence of CMP-Neu5Ac. N. gonorrhoeae strain 1291 formed a biofilm on primary urethral epithelial cells and cervical cells in culture without loss of viability of the epithelial cell layer. Our studies demonstrated that N. gonorrhoeae can form biofilms in continuous-flow chambers and on living cells. Studies of these biofilms may have implications for understanding asymptomatic gonococcal infection.
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Affiliation(s)
- L L Greiner
- Department of Microbiology, University of Iowa, 51 Newton Rd., Iowa City, IA 52242, USA.
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