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Article ; Online: Pseudomonas aeruginosa Triggered Exosomal Release of ADAM10 Mediates Proteolytic Cleavage in Trans

Ahmad Aljohmani / Bastian Opitz / Markus Bischoff / Daniela Yildiz

International Journal of Molecular Sciences, Vol 23, Iss 1259, p

2022 Volume 1259

Abstract: Pneumonia is a life-threatening disease often caused by infection with Streptococcus pneumoniae and Pseudomonas aeruginosa . Many of the mediators (e.g., TNF, IL-6R) and junction molecules (e.g., E-cadherin) orchestrating inflammatory cell recruitment ... ...

Abstract	Pneumonia is a life-threatening disease often caused by infection with Streptococcus pneumoniae and Pseudomonas aeruginosa . Many of the mediators (e.g., TNF, IL-6R) and junction molecules (e.g., E-cadherin) orchestrating inflammatory cell recruitment and loss of barrier integrity are proteolytically cleaved through a disintegrin and metalloproteinases (ADAMs). We could show by Western blot, surface expression analysis and measurement of proteolytic activity in cell-based assays, that ADAM10 in epithelial cells is upregulated and activated upon infection with Pseudomonas aeruginosa and Exotoxin A (ExoA), but not upon infection with Streptococcus pneumoniae . Targeting ADAM10 by pharmacological inhibition or gene silencing, we demonstrated that this activation was critical for cleavage of E-cadherin and modulated permeability and epithelial integrity. Stimulation with heat-inactivated bacteria revealed that the activation was based on the toxin repertoire rather than the interaction with the bacterial particle itself. Furthermore, calcium imaging experiments showed that the ExoA action was based on the induction of calcium influx. Investigating the extracellular vesicles and their proteolytic activity, we could show that Pseudomonas aeruginosa triggered exosomal release of ADAM10 and proteolytic cleavage in trans. This newly described mechanism could constitute an essential mechanism causing systemic inflammation in patients suffering from Pseudomonas aeruginosa -induced pneumonia stimulating future translational studies.
Keywords	proteolysis ; metalloproteinase ; infection ; exosomes ; cell-cell-communication ; Biology (General) ; QH301-705.5 ; Chemistry ; QD1-999
Subject code	572
Language	English
Publishing date	2022-01-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Role of Extracellular Vimentin in Cancer-Cell Functionality and Its Influence on Cell Monolayer Permeability Changes Induced by SARS-CoV-2 Receptor Binding Domain

Divyendu Goud Thalla / Philipp Jung / Markus Bischoff / Franziska Lautenschläger

International Journal of Molecular Sciences, Vol 22, Iss 7469, p

2021 Volume 7469

Abstract: The cytoskeletal protein vimentin is secreted under various physiological conditions. Extracellular vimentin exists primarily in two forms: attached to the outer cell surface and secreted into the extracellular space. While surface vimentin is involved ... ...

Abstract	The cytoskeletal protein vimentin is secreted under various physiological conditions. Extracellular vimentin exists primarily in two forms: attached to the outer cell surface and secreted into the extracellular space. While surface vimentin is involved in processes such as viral infections and cancer progression, secreted vimentin modulates inflammation through reduction of neutrophil infiltration, promotes bacterial elimination in activated macrophages, and supports axonal growth in astrocytes through activation of the IGF-1 receptor. This receptor is overexpressed in cancer cells, and its activation pathway has significant roles in general cellular functions. In this study, we investigated the functional role of extracellular vimentin in non-tumorigenic (MCF-10a) and cancer (MCF-7) cells through the evaluation of its effects on cell migration, proliferation, adhesion, and monolayer permeability. Upon treatment with extracellular recombinant vimentin, MCF-7 cells showed increased migration, proliferation, and adhesion, compared to MCF-10a cells. Further, MCF-7 monolayers showed reduced permeability, compared to MCF-10a monolayers. It has been shown that the receptor binding domain of SARS-CoV-2 spike protein can alter blood–brain barrier integrity. Surface vimentin also acts as a co-receptor between the SARS-CoV-2 spike protein and the cell-surface angiotensin-converting enzyme 2 receptor. Therefore, we also investigated the permeability of MCF-10a and MCF-7 monolayers upon treatment with extracellular recombinant vimentin, and its modulation of the SARS-CoV-2 receptor binding domain. These findings show that binding of extracellular recombinant vimentin to the cell surface enhances the permeability of both MCF-10a and MCF-7 monolayers. However, with SARS-CoV-2 receptor binding domain addition, this effect is lost with MCF-7 monolayers, as the extracellular vimentin binds directly to the viral domain. This defines an influence of extracellular vimentin in SARS-CoV-2 infections.
Keywords	extracellular vimentin ; IGF-1 receptor ; cancer ; SARS-CoV-2 receptor binding domain ; Biology (General) ; QH301-705.5 ; Chemistry ; QD1-999
Subject code	500
Language	English
Publishing date	2021-07-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: T cell stiffness is enhanced upon formation of immunological synapse

Philipp Jung / Xiangda Zhou / Sandra Iden / Markus Bischoff / Bin Qu

eLife, Vol

2021 Volume 10

Abstract: T cells are activated by target cells via an intimate contact, termed immunological synapse (IS). Cellular mechanical properties, especially stiffness, are essential to regulate cell functions. However, T cell stiffness at a subcellular level at the IS ... ...

Abstract	T cells are activated by target cells via an intimate contact, termed immunological synapse (IS). Cellular mechanical properties, especially stiffness, are essential to regulate cell functions. However, T cell stiffness at a subcellular level at the IS still remains largely elusive. In this work, we established an atomic force microscopy (AFM)-based elasticity mapping method on whole T cells to obtain an overview of the stiffness with a resolution of ~60 nm. Using primary human CD4+ T cells, we show that when T cells form IS with stimulating antibody-coated surfaces, the lamellipodia are stiffer than the cell body. Upon IS formation, T cell stiffness is enhanced both at the lamellipodia and on the cell body. Chelation of intracellular Ca2+ abolishes IS-induced stiffening at the lamellipodia but has no influence on cell-body-stiffening, suggesting different regulatory mechanisms of IS-induced stiffening at the lamellipodia and the cell body.
Keywords	T cells ; stiffness ; immunological synapse ; lamellipodia ; calcium ; primary CD4+ T cells ; Medicine ; R ; Science ; Q ; Biology (General) ; QH301-705.5
Language	English
Publishing date	2021-07-01T00:00:00Z
Publisher	eLife Sciences Publications Ltd
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: The Low-Molecular Weight Protein Arginine Phosphatase PtpB Affects Nuclease Production, Cell Wall Integrity, and Uptake Rates of Staphylococcus aureus by Polymorphonuclear Leukocytes

Mohamed Ibrahem Elhawy / Virginie Molle / Sören L. Becker / Markus Bischoff

International Journal of Molecular Sciences, Vol 22, Iss 5342, p

2021 Volume 5342

Abstract: The epidemiological success of Staphylococcus aureus as a versatile pathogen in mammals is largely attributed to its virulence factor repertoire and the sophisticated regulatory network controlling this virulon. Here we demonstrate that the low-molecular- ...

Abstract	The epidemiological success of Staphylococcus aureus as a versatile pathogen in mammals is largely attributed to its virulence factor repertoire and the sophisticated regulatory network controlling this virulon. Here we demonstrate that the low-molecular-weight protein arginine phosphatase PtpB contributes to this regulatory network by affecting the growth phase-dependent transcription of the virulence factor encoding genes/operons aur , nuc , and psm α , and that of the small regulatory RNA RNAIII . Inactivation of ptpB in S. aureus SA564 also significantly decreased the capacity of the mutant to degrade extracellular DNA, to hydrolyze proteins in the extracellular milieu, and to withstand Triton X-100 induced autolysis. SA564 Δ ptpB mutant cells were additionally ingested faster by polymorphonuclear leukocytes in a whole blood phagocytosis assay, suggesting that PtpB contributes by several ways positively to the ability of S. aureus to evade host innate immunity.
Keywords	Staphylococcus aureus ; low-molecular-weight protein arginine phosphatase ; PtpB ; nuclease ; whole blood phagocytosis assay ; cell wall integrity ; Biology (General) ; QH301-705.5 ; Chemistry ; QD1-999
Subject code	571
Language	English
Publishing date	2021-05-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Using Knock-Out Mutants to Investigate the Adhesion of Staphylococcus aureus to Abiotic Surfaces

Christian Spengler / Friederike Nolle / Nicolas Thewes / Ben Wieland / Philipp Jung / Markus Bischoff / Karin Jacobs

International Journal of Molecular Sciences, Vol 22, Iss 11952, p

2021 Volume 11952

Abstract: The adhesion of Staphylococcus aureus to abiotic surfaces is crucial for establishing device-related infections. With a high number of single-cell force spectroscopy measurements with genetically modified S. aureus cells, this study provides insights ... ...

Abstract	The adhesion of Staphylococcus aureus to abiotic surfaces is crucial for establishing device-related infections. With a high number of single-cell force spectroscopy measurements with genetically modified S. aureus cells, this study provides insights into the adhesion process of the pathogen to abiotic surfaces of different wettability. Our results show that S. aureus utilizes different cell wall molecules and interaction mechanisms when binding to hydrophobic and hydrophilic surfaces. We found that covalently bound cell wall proteins strongly interact with hydrophobic substrates, while their contribution to the overall adhesion force is smaller on hydrophilic substrates. Teichoic acids promote adhesion to hydrophobic surfaces as well as to hydrophilic surfaces. This, however, is to a lesser extent. An interplay of electrostatic effects of charges and protein composition on bacterial surfaces is predominant on hydrophilic surfaces, while it is overshadowed on hydrophobic surfaces by the influence of the high number of binding proteins. Our results can help to design new models of bacterial adhesion and may be used to interpret the adhesion of other microorganisms with similar surface properties.
Keywords	bacterial adhesion ; single-cell force spectroscopy ; Staphylococcus aureus ; Staphylococcus aureus knock-out mutants ; surface charge ; hydrophobicity ; Biology (General) ; QH301-705.5 ; Chemistry ; QD1-999
Subject code	540 ; 612
Language	English
Publishing date	2021-11-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: IL-17C and IL-17RE Promote Wound Closure in a Staphylococcus aureus -Based Murine Wound Infection Model

Linda Pätzold / Alexandra Stark / Felix Ritzmann / Carola Meier / Thomas Tschernig / Jörg Reichrath / Robert Bals / Markus Bischoff / Christoph Beisswenger

Microorganisms, Vol 9, Iss 1821, p

2021 Volume 1821

Abstract: The epithelial cytokine interleukin-17C (IL-17C) mediates inflammation through the interleukin 17 receptor E (IL-17RE). Prior studies showed a detrimental role of IL-17C in the pathogenesis of immune-mediated skin diseases (e.g., psoriasis). Here, we ... ...

Abstract	The epithelial cytokine interleukin-17C (IL-17C) mediates inflammation through the interleukin 17 receptor E (IL-17RE). Prior studies showed a detrimental role of IL-17C in the pathogenesis of immune-mediated skin diseases (e.g., psoriasis). Here, we examined the role of IL-17C/IL-17RE in wound closure in a Staphylococcus aureus wound infection model. We demonstrate that wound closure is significantly delayed in IL-17RE ( Il-17re −/− )- and 17C ( Il-17c −/− )-deficient mice. There was no significant difference between WT, Il-17re −/− , and Il-17c −/− mice in the absence of infection. Deficiency for IL-17RE and IL-17C did not significantly affect the elimination of bacteria. IL-17C expression was increased in the epidermis of human S. aureus -infected skin. Our results indicate that the IL-17C/IL-17RE axis contributes to the closure of infected wounds but does not contribute to the elimination of S. aureus .
Keywords	Staphylococcus aureus ; wound infection ; interleukin-17C ; wound closure ; Biology (General) ; QH301-705.5
Language	English
Publishing date	2021-08-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Prevalence, antimicrobial susceptibility and genotypic characteristics of Staphylococcus aureus in Tanzania

Tutu Mzee / Theckla Kazimoto / Joseph Madata / Rose Masalu / Markus Bischoff / Mecky Matee / Sören L. Becker

Bulletin of the National Research Centre, Vol 45, Iss 1, Pp 1-

a systematic review

2021 Volume 21

Abstract: Abstract Background Data on the prevalence, genotypes and antibiotic resistance patterns of colonizing and infection-associated Staphylococcus aureus (S. aureus) strains both in humans and animals in Tanzania are scarce. Given the wide range of ... ...

Abstract	Abstract Background Data on the prevalence, genotypes and antibiotic resistance patterns of colonizing and infection-associated Staphylococcus aureus (S. aureus) strains both in humans and animals in Tanzania are scarce. Given the wide range of infections caused by S. aureus and the rise of methicillin-resistant S. aureus (MRSA) globally, this review aims at collecting published data on S. aureus bacterium to improve our understanding of its epidemiology in Tanzania. Main body We carried out a systematic review of scientific studies reporting on prevalence, antibiotic resistance and genotyping data pertaining to S. aureus in human and animal infection and colonization. The literature extracted from electronic databases such as PubMed and Google Scholar was screened for eligibility and relevant articles were included. The review is limited to manuscripts published in English language between the years 2010 and 2020. A total of 45 studies conducted in 7 of the 9 administrative zones in Tanzania were reviewed to gather data on S. aureus prevalence in humans and animals. Prevalence in humans ranged from 1 to 60%. Antibiotic resistance patterns of S. aureus isolated from colonized humans showed high resistance rates against co-trimoxazole (46%) and erythromycin (41%) as compared to reports from studies conducted outside Africa. The review suggests an increased MRSA prevalence of up to 26% as compared to 6–16% reported in previous years. Genotypic data reviewed suggested that MRSA predominantly belonged to ST88. The prevalence of S. aureus in animal studies ranged from 33 to 49%, with 4 to 35% of MRSA isolates. Most studies reported low antibiotic resistance levels, with the exception of penicillin (85%) and ampicillin (73%). Conclusion The prevalence of S. aureus and MRSA in Tanzania is rising, although clear variations between different geographic areas could be observed. Non-susceptibility to commonly prescribed antibiotics in community-associated S. aureus is of concern. Research strategies to ameliorate our ...
Keywords	Staphylococcus aureus ; Prevalence ; Antimicrobial resistance ; Genotyping ; Infection ; Colonization ; Science ; Q
Subject code	306
Language	English
Publishing date	2021-09-01T00:00:00Z
Publisher	SpringerOpen
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Quantification of the Adhesion Strength of Candida albicans to Tooth Enamel

Gubesh Gunaratnam / Johanna Dudek / Philipp Jung / Sören L. Becker / Karin Jacobs / Markus Bischoff / Matthias Hannig

Microorganisms, Vol 9, Iss 2213, p

2021 Volume 2213

Abstract: Caries is one of the most prevalent diseases worldwide, which is caused by the degradation of the tooth enamel surface. In earlier research the opportunistic pathogen Candida albicans has been associated with the formation of caries in children. ... ...

Abstract	Caries is one of the most prevalent diseases worldwide, which is caused by the degradation of the tooth enamel surface. In earlier research the opportunistic pathogen Candida albicans has been associated with the formation of caries in children. Colonization of teeth by C. albicans starts with the initial adhesion of individual yeast cells to the tooth enamel surface. In this study, we visualized the initial colonization of C. albicans yeast cells on pellicle-covered enamel by scanning electron microscopy. To quantitatively unravel the initial adhesion strength, we applied fluidic force microscopy-based single-cell force spectroscopy to examine the key adhesion parameters adhesion force, rupture length and de-adhesion work. We analyzed single saliva-treated or untreated yeast cells on tooth enamel specimens with or without salivary pellicle. Under all tested conditions, adhesion forces in the lower nanonewton range were determined. Furthermore, we have found that all adhesion parameters were enhanced on the pellicle-covered compared to the uncovered enamel. Our data suggest that initial adhesion occurs through a strong interaction between yeast cell wall-associated adhesins and the salivary pellicle. Future SCFS studies may show whether specific management of the salivary pellicle reduces the adhesion of C. albicans on teeth and thus contributes to caries prophylaxis.
Keywords	single-cell force spectroscopy ; Candida albicans ; dental caries ; adhesion ; Biology (General) ; QH301-705.5
Language	English
Publishing date	2021-10-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: The Phosphoarginine Phosphatase PtpB from Staphylococcus aureus Is Involved in Bacterial Stress Adaptation during Infection

Mohamed Ibrahem Elhawy / Sylvaine Huc-Brandt / Linda Pätzold / Laila Gannoun-Zaki / Ahmed Mohamed Mostafa Abdrabou / Markus Bischoff / Virginie Molle

Cells, Vol 10, Iss 645, p

2021 Volume 645

Abstract: Staphylococcus aureus continues to be a public health threat, especially in hospital settings. Studies aimed at deciphering the molecular and cellular mechanisms that underlie pathogenesis, host adaptation, and virulence are required to develop effective ...

Abstract	Staphylococcus aureus continues to be a public health threat, especially in hospital settings. Studies aimed at deciphering the molecular and cellular mechanisms that underlie pathogenesis, host adaptation, and virulence are required to develop effective treatment strategies. Numerous host-pathogen interactions were found to be dependent on phosphatases-mediated regulation. This study focused on the analysis of the role of the low-molecular weight phosphatase PtpB, in particular, during infection. Deletion of ptpB in S. aureus strain SA564 significantly reduced the capacity of the mutant to withstand intracellular killing by THP-1 macrophages. When injected into normoglycemic C57BL/6 mice, the SA564 Δ ptpB mutant displayed markedly reduced bacterial loads in liver and kidney tissues in a murine S. aureus abscess model when compared to the wild type. We also observed that PtpB phosphatase-activity was sensitive to oxidative stress. Our quantitative transcript analyses revealed that PtpB affects the transcription of various genes involved in oxidative stress adaptation and infectivity. Thus, this study disclosed first insights into the physiological role of PtpB during host interaction allowing us to link phosphatase-dependent regulation to oxidative bacterial stress adaptation during infection.
Keywords	Staphylococcus aureus ; arginine phosphatase ; infection ; oxidative response ; Biology (General) ; QH301-705.5
Subject code	572
Language	English
Publishing date	2021-03-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Impact of the Histidine-Containing Phosphocarrier Protein HPr on Carbon Metabolism and Virulence in Staphylococcus aureus

Linda Pätzold / Anne-Christine Brausch / Evelyn-Laura Bielefeld / Lisa Zimmer / Greg A. Somerville / Markus Bischoff / Rosmarie Gaupp

Microorganisms, Vol 9, Iss 3, p

2021 Volume 466

Abstract: Carbon catabolite repression (CCR) is a common mechanism pathogenic bacteria use to link central metabolism with virulence factor synthesis. In gram-positive bacteria, catabolite control protein A (CcpA) and the histidine-containing phosphocarrier ... ...

Abstract	Carbon catabolite repression (CCR) is a common mechanism pathogenic bacteria use to link central metabolism with virulence factor synthesis. In gram-positive bacteria, catabolite control protein A (CcpA) and the histidine-containing phosphocarrier protein HPr (encoded by ptsH ) are the predominant mediators of CCR. In addition to modulating CcpA activity, HPr is essential for glucose import via the phosphotransferase system. While the regulatory functions of CcpA in Staphylococcus aureus are largely known, little is known about the function of HPr in CCR and infectivity. To address this knowledge gap, ptsH mutants were created in S. aureus that either lack the open reading frame or harbor a ptsH variant carrying a thymidine to guanosine mutation at position 136, and the effects of these mutations on growth and metabolism were assessed. Inactivation of ptsH altered bacterial physiology and decreased the ability of S. aureus to form a biofilm and cause infections in mice. These data demonstrate that HPr affects central metabolism and virulence in S. aureus independent of its influence on CcpA regulation.
Keywords	Staphylococcus aureus ; physiology ; metabolism ; carbon catabolite repression ; CcpA ; HPr ; Biology (General) ; QH301-705.5
Subject code	572
Language	English
Publishing date	2021-02-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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