Helicobacter pylori Outer Membrane Vesicles Protect the Pathogen From Reactive Oxygen Species of the Respiratory Burst

Lekmeechai, Sujinna; Su, Yu-Ching; Brant, Marta; Alvarado-Kristensson, María; Vallström, Anna; Obi, Ikenna; Arnqvist, Anna; Riesbeck, Kristian

doi:10.3389/fmicb.2018.01837

Cited by 60 publications

(54 citation statements)

References 17 publications

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“…Consistent with the recent report by Lekmeechai et al [23], but using a different H. pylori strain, we found that addition of purified OMVs could enhance H. pylori survival of hydrogen peroxide treatment in a dosedependent manner. Using a katA mutant, Lekmeechai et al [23] showed that the protective effects of H. pylori OMV against hydrogen peroxide were mediated by the catalase enzyme.…”

Section: Discussionsupporting

confidence: 93%

“…H. pylori OMVs are enriched with catalase [23], which is thought to contribute to bacterial survival of oxidative stress in the human stomach. We treated H. pylori with 1 mM H 2 O 2 and measured bacterial survival using colony counts after 2.5 h. H 2 O 2 treatment caused greater than 8-log reduction in c.f.u.…”

Section: Membrane Vesicles Can Protect H Pylori Against Hydrogen Permentioning

confidence: 99%

“…Protective effects of OMVs against oxidative stress in H. pylori were recently reported using strains P12 and 18943 [23]. If the production of OMV can help H. pylori to survive stressors such as the host immune response and antibiotic treatment, then it might be possible to increase the susceptibility of H. pylori to immunity and therapy, and/or reduce the virulence of the infection, by designing new therapies that interfere with vesiculation.…”

Section: Introductionmentioning

confidence: 99%

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Protective effects of Helicobacter pylori membrane vesicles against stress and antimicrobial agents

et al. 2020

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Outer-membrane vesicles (OMVs) produced by Helicobacter pylori deliver bacterial components to host cells, provide a mechanism for stabilization of secreted components and may allow the bacteria to exert ‘long-range’ effects in the gastric niche, promoting persistence. In addition to their well-characterized host cell interactions, membrane vesicles improve stress survival in other bacterial species, and are constitutively produced by both pathogenic and non-pathogenic bacteria. We aimed to determine whether OMVs could improve H. pylori survival of a range of stressors. The effects of purified OMVs on the resistance of H. pylori to a range of environmental and antimicrobial stresses were determined using growth curves and survival assays. Addition of purified OMVs to H. pylori cultures provided dose-dependent protection against hydrogen peroxide-mediated killing. Supplementation with OMVs also partially protected H. pylori against the bactericidal effects of the antibiotics clarithromycin and levofloxacin, but not against amoxicillin nor metronidazole. Addition of purified OMVs allowed H. pylori to grow in the presence of inhibitory concentrations of the antimicrobial peptide LL-37. In the presence of 50 µg OMVs ml−1, significantly enhanced H. pylori growth was observed at higher LL-37 concentrations compared with lower LL-37 concentrations, suggesting that OMV–LL-37 interactions might facilitate release of growth-promoting nutrients. Taken together, these data indicate that production of membrane vesicles could help H. pylori to survive exposure to antibiotics and host antimicrobial defences during infection.

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Section: Discussionsupporting

confidence: 93%

Section: Membrane Vesicles Can Protect H Pylori Against Hydrogen Permentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Protective effects of Helicobacter pylori membrane vesicles against stress and antimicrobial agents

et al. 2020

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“…Many bacteria use such enzymes to safeguard against stressful environmental conditions and immune cell defenses. One example is Helicobacter pylori OMVs, which contain a catalase-like protein (KatB) and are shown to be protective against ROS from immune cell respiratory bursts [53]. B. burgdorferi uses a superoxide dismutase, which has been shown to be an essential virulence factor for infection of mice [54].…”

Section: Discussionmentioning

confidence: 99%

Effect of Borrelia burgdorferi Outer Membrane Vesicles on Host Oxidative Stress Response

et al. 2020

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Outer membrane vesicles (OMVs) are spherical bodies containing proteins and nucleic acids that are released by Gram-negative bacteria, including Borrelia burgdorferi, the causative agent of Lyme disease. The functional relationship between B. burgdorferi OMVs and host neuron homeostasis is not well understood. The objective of this study was to examine how B. burgdorferi OMVs impact the host cell environment. First, an in vitro model was established by co-culturing human BE2C neuroblastoma cells with B. burgdorferi B31. B. burgdorferi was able to invade BE2C cells within 24 h. Despite internalization, BE2C cell viability and levels of apoptosis remained unchanged, but resulted in dramatically increased production of MCP-1 and MCP-2 cytokines. Elevated secretion of MCP-1 has previously been associated with changes in oxidative stress. BE2C cell mitochondrial superoxides were reduced as early as 30 min after exposure to B. burgdorferi and OMVs. To rule out whether BE2C cell antioxidant response is the cause of decline in superoxides, superoxide dismutase 2 (SOD2) gene expression was assessed. SOD2 expression was reduced upon exposure to B. burgdorferi, suggesting that B. burgdorferi might be responsible for superoxide reduction. These results suggest that B. burgdorferi modulates cell antioxidant defense and immune system reaction in response to the bacterial infection. In summary, these results show that B. burgdorferi OMVs serve to directly counter superoxide production in BE2C neurons, thereby ‘priming’ the host environment to support B. burgdorferi colonization.

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“…Intra- and interspecies communication, defense, the uptake of resources, the release of metabolic byproducts, detoxification, responsiveness to abrupt envelope stresses, horizontal gene transfer, acting as ‘decoy’ agents, as well as functioning as public goods, are among the proposed roles of bacterial EVs [ 40 , 48 ] ( Figure 4 ). For instance, Helicobacter pylori releases EVs selectively decorated with catalase KatA on their surface, which contributes to neutralizing reactive oxygen species from the host, working as a mechanism to aid in evading host immune responses during infection [ 85 ]. Interestingly, H. pylori EVs showed a better performance in hydrogen peroxide detoxification than whole-cell lysates [ 85 ].…”

Section: Evs’ Biological Rolesmentioning

confidence: 99%

Extracellular Vesicles: An Overlooked Secretion System in Cyanobacteria

Lima

Matinha-Cardoso

Tamagnini

et al. 2020

Life

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In bacteria, the active transport of material from the interior to the exterior of the cell, or secretion, represents a very important mechanism of adaptation to the surrounding environment. The secretion of various types of biomolecules is mediated by a series of multiprotein complexes that cross the bacterial membrane(s), each complex dedicated to the secretion of specific substrates. In addition, biological material may also be released from the bacterial cell in the form of vesicles. Extracellular vesicles (EVs) are bilayered, nanoscale structures, derived from the bacterial cell envelope, which contain membrane components as well as soluble products. In cyanobacteria, the knowledge regarding EVs is lagging far behind compared to what is known about, for example, other Gram-negative bacteria. Here, we present a summary of the most important findings regarding EVs in Gram-negative bacteria, discussing aspects of their composition, formation processes and biological roles, and highlighting a number of technological applications tested. This lays the groundwork to raise awareness that the release of EVs by cyanobacteria likely represents an important, and yet highly disregarded, survival strategy. Furthermore, we hope to motivate future studies that can further elucidate the role of EVs in cyanobacterial cell biology and physiology.

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Helicobacter pylori Outer Membrane Vesicles Protect the Pathogen From Reactive Oxygen Species of the Respiratory Burst

Cited by 60 publications

References 17 publications

Protective effects of Helicobacter pylori membrane vesicles against stress and antimicrobial agents

Protective effects of Helicobacter pylori membrane vesicles against stress and antimicrobial agents

Effect of Borrelia burgdorferi Outer Membrane Vesicles on Host Oxidative Stress Response

Extracellular Vesicles: An Overlooked Secretion System in Cyanobacteria

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