Bacteriophages immunomodulate the response of monocytes

2021 ◽  
pp. 153537022199515
Author(s):  
Lídia Perea ◽  
Lorena Rodríguez-Rubio ◽  
Juan C Nieto ◽  
Carlos Zamora ◽  
Elisabet Cantó ◽  
...  
Keyword(s):  
Cytokine Production ◽  
Statistical Significance ◽  
Control Sample ◽  
Polymyxin B ◽  
Dependent Manner ◽  
Direct Role ◽  
Gram Positive Bacteria ◽  
Hla Dr ◽  
Tnf Α

Bacteriophages are present in fluids from cirrhosis patients. However, their effect on the immune response is unknown. In this work, we explore the role of phages in the phenotype, function, and cytokine production of monocytes. We stimulated healthy monocytes with five different butanol-purified phage suspensions infective for Gram-negative and Gram-positive bacteria. We studied the expression of the monocyte markers involved in lipopolysaccharide recognition (LPS; CD14), antigen presentation (HLA-DR) and co-stimulation (CD86), and the concentration of induced cytokines (TNF-α, IFN-α, and IL-10) by phages. To confirm the direct role of phages without the interference of contaminating soluble LPS in phage suspensions, polymyxin B was added to the cell cultures. Phagocytosis experiments were assessed by flow cytometry using labeled phage suspensions. We observed that butanol-purified phages reduced the surface levels of CD14 and CD86 in monocytes and increased the secreted levels of TNF-α and IL-10 compared with the control sample containing only butanol buffer. All phage suspensions showed downregulation of HLA-DR expression but only Staphylococcus aureus phage contaminated with Escherichia coli reached statistical significance. The addition of polymyxin B did not restore the monocytic response induced by phages, suggesting that the effect was not caused by the presence of LPS. Monocytes were able to phagocyte phages in a dose- and time-dependent manner. To conclude, the phagocytosis of butanol-purified phages altered the phenotype and cytokine production of monocytes suggesting they become tolerogenic.

scholarly journals Macrophage Inflammatory Response Mediated by Intimin and Bundle-Forming Pilus from Enteropathogenic Escherichia coli

Proceedings ◽  
2020 ◽  
Vol 66 (1) ◽  
pp. 21
Author(s):  
Bruna A. Caetano ◽  
Daniela B. Mourão ◽  
Patrícia A. E. Abreu ◽  
Denize Monaris ◽  
Halyka L. Vasconcellos ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Inflammatory Cytokines ◽  
Polymyxin B ◽  
Effector Proteins ◽  
Dependent Manner ◽  
Enteropathogenic Escherichia Coli ◽  
Tnf Α ◽  
Anti Inflammatory

Enteropathogenic Escherichia coli (EPEC) are important agents of acute diarrhea in children living in developing countries. A severe dysfunction of the intestinal epithelial barrier occurs during EPEC infection, leading to diarrhea and inflammation as consequences. EPEC main virulence factors include the adhesins intimin and bundle-forming pilus (BFP), as well as several effector proteins translocated to the enterocyte by the type-three secretion system. The initial interaction of EPEC with the host cell and the role of effector proteins in this process are well known. However, the role of the EPEC virulence factors in macrophage activation is not fully understood. Hence, we analyzed the ability of intimin and bundle-forming pilus (BfpA) to activate the innate response mediated by macrophages, where the production of the proinflammatory cytokines TNF-α, IL-1, IL-6 and IL-12, as well as the anti-inflammatory cytokine IL-10 and chemokine MCP-1, were evaluated. Our results showed that recombinant intimin and BfpA activate macrophages in a dose-dependent manner, and the stimulated cells produced TNF-α, IL-12, IL-6, IL-10 and MCP-1, but not IL-1β. No synergistic effect was observed in the production of pro-inflammatory cytokines by combining BfpA and intimin, although production of IL-10, an anti-inflammatory mediator, was potentiated at a higher dose. The effect observed was largely attributed to these proteins, as the treatment of proteins with polymyxin B did not alter the production of TNF-α. Thus, herein we showed that intimin and BfpA can activate the innate immune response, inducing the production of pro- and anti-inflammatory cytokines, as well as chemokines, playing additional role as inflammatory molecules in the early steps of EPEC infection.

scholarly journals PapRIV, a BV-2 microglial cell activating quorum sensing peptide

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yorick Janssens ◽  
Nathan Debunne ◽  
Anton De Spiegeleer ◽  
Evelien Wynendaele ◽  
Marta Planas ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Cell Model ◽  
Dependent Manner ◽  
Communication Signals ◽  
Gram Positive Bacteria ◽  
A Cell ◽  
Gastro Intestinal Tract

AbstractQuorum sensing peptides (QSPs) are bacterial peptides produced by Gram-positive bacteria to communicate with their peers in a cell-density dependent manner. These peptides do not only act as interbacterial communication signals, but can also have effects on the host. Compelling evidence demonstrates the presence of a gut-brain axis and more specifically, the role of the gut microbiota in microglial functioning. The aim of this study is to investigate microglial activating properties of a selected QSP (PapRIV) which is produced by Bacillus cereus species. PapRIV showed in vitro activating properties of BV-2 microglia cells and was able to cross the in vitro Caco-2 cell model and reach the brain. In vivo peptide presence was also demonstrated in mouse plasma. The peptide caused induction of IL-6, TNFα and ROS expression and increased the fraction of ameboid BV-2 microglia cells in an NF-κB dependent manner. Different metabolites were identified in serum, of which the main metabolite still remained active. PapRIV is thus able to cross the gastro-intestinal tract and the blood–brain barrier and shows in vitro activating properties in BV-2 microglia cells, hereby indicating a potential role of this quorum sensing peptide in gut-brain interaction.

scholarly journals Bitter Taste Receptor T2R14 Modulates Gram-Positive Bacterial Internalization and Survival in Gingival Epithelial Cells

2021 ◽  
Vol 22 (18) ◽  
pp. 9920
Author(s):  
Manoj Reddy Medapati ◽  
Anjali Yadav Bhagirath ◽  
Nisha Singh ◽  
Robert J. Schroth ◽  
Rajinder P. Bhullar ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Bitter Taste ◽  
Taste Receptor ◽  
Gram Positive ◽  
Direct Role ◽  
Gram Positive Bacteria ◽  
Inhibition Of Growth ◽  
Gingival Epithelial Cells ◽  
Underlying Mechanisms

Bitter-taste receptors (T2Rs) have emerged as key players in host–pathogen interactions and important modulators of oral innate immunity. Previously, we reported that T2R14 is expressed in gingival epithelial cells (GECs) and interacts with competence stimulating peptides (CSPs) secreted by the cariogenic Streptococcus mutans. The underlying mechanisms of the innate immune responses and physiological effects of T2R14 on Gram-positive bacteria are not well characterized. In this study, we examined the role of T2R14 in internalization and growth inhibitory effects on Gram-positive bacteria, namely Staphylococcus aureus and S. mutans. We utilized CRISPR-Cas9 T2R14 knockdown (KD) GECs as the study model to address these key physiological mechanisms. Our data reveal that the internalization of S. aureus is significantly decreased, while the internalization of S. mutans remains unaffected upon knockdown of T2R14 in GECs. Surprisingly, GECs primed with S. mutans CSP-1 resulted in an inhibition of growth for S. aureus, but not for S. mutans. The GECs infected with S. aureus induced T2R14-dependent human β-defensin-2 (hBD-2) secretion; however, S. mutans–infected GECs did not induce hBD-2 secretion, but induced T2R14 dependent IL-8 secretion. Interestingly, our results show that T2R14 KD affects the cytoskeletal reorganization in GECs, thereby inhibiting S. aureus internalization. Our study highlights the distinct mechanisms and a direct role of T2R14 in influencing physiological responses to Gram-positive bacteria in the oral cavity.

The Anti-Inflammatory Potential of Mimosa caesalpiniifolia Following Experimental Colitis: Role of COX-2 and TNF-Alpha Expression

Drug Research ◽  
2017 ◽  
Vol 68 (04) ◽  
pp. 196-204 ◽  
Author(s):  
Marcelo Silva ◽  
Wagner Vilegas ◽  
Marcelo da Silva ◽  
Ana Paiotti ◽  
Mauricio Pastrelo ◽  
...  
Keyword(s):  
Protective Action ◽  
Experimental Colitis ◽  
Distal Colon ◽  
Tnf Alpha ◽  
High Dose ◽  
Dependent Manner ◽  
Hydroalcoholic Extract ◽  
Tnf Α ◽  
Cox 2

AbstractThe aim of this study was to evaluate the preventive and/or protective action of Mimosa caesalpiniifolia (M. caesalpiniifolia) following experimental colitis in rats. The rats were randomized into ten groups (n=10 per group), as follows: G1 – Sham group:; G2 – TNBS group; G3, G4 –colitis and treated with hydroalcoholic extract of M. caesalpiniifolia 250 mg/kg/day after and before/after inducing colitis, respectively; G5, G6 – colitis and treated with hydroalcoholic extract of M. caesalpiniifolia at 125 mg/kg/day after and before/after inducing colitis respectively; G7,G8 – colitis and treated with ethylacetate fraction of M. caesalpiniifolia at 50 mg/kg/day after and before/after inducing colitis, respectively; G9,G10 – colitis and treated with ethylacetate fraction of M. caesalpiniifolia at 50 mg/kg/day after and before/after inducing colitis, respectively. Rats treated with hydroalcoholic extract of M. caesalpiniifolia for both doses showed lower tissue damage in the distal colon. Ethylacetate fraction was effective at the highest dose only when administrated after inducing colitis. A downregulation of COX-2 was detected to rats suffering colitis and treated with M. caesalpiniifolia at high dose. On the other hand, TNF-alpha immunoexpression decreased in groups treated with M. caesalpiniifolia at low dose after inducing colitis. In summary, our results suggest that M. caesalpiniifolia attenuated the lesions of the colon, reduced inflammation, and modulates the expression of COX-2 and TNF-α during chronic colitis induced by TNBS when using for therapeutic purposes on a dose-dependent manner.

Effects of tributyltin on placental cytokine production

2018 ◽  
Vol 46 (8) ◽  
pp. 867-875 ◽  
Author(s):  
Yuko Arita ◽  
Michael Kirk ◽  
Neha Gupta ◽  
Ramkumar Menon ◽  
Darios Getahun ◽  
...  
Keyword(s):  
Tumor Necrosis ◽  
Cytokine Production ◽  
Heme Oxygenase 1 ◽  
Dependent Manner ◽  
Neurodevelopmental Outcomes ◽  
Placental Function ◽  
Tnf Α ◽  
Explant Cultures ◽  
High Doses ◽  
Necrosis Factor

Abstract Objective Tributyltin (TBT) is a persistent pollutant but its effects on placental function are poorly understood as are its possible interactions with infection. We hypothesized that TBT alters the production of sex hormones and biomarkers for inflammation and neurodevelopment in an infection-dependent manner. Methods Placental explant cultures were treated with 0–5000 nM TBT in the presence and absence of Escherichia coli. A conditioned medium was harvested and concentrations of steroids (progesterone, P4; testosterone, T and estradiol, E2) as well as biomarkers of inflammation [interleukin (IL)-1β (IL-1β), tumor necrosis factor (TNF-α), IL-10, IL-6, soluble glycoprotein 130 (sgp-130) and heme oxygenase-1 (HO-1)], oxidative stress [8-iso-prostaglandin (8-IsoP)] and neurodevelopment [brain-derived neurotrophic factor (BDNF)] were quantified. Results TBT increased P4 slightly but had little or no effect on T or E2 production. IL-1β, IL-6, sgp-130, IL-10 and 8-IsoP production was enhanced by TBT. P4 and IL-6 production was also enhanced by TBT for bacteria-stimulated cultures but TBT significantly inhibited bacteria-induced IL-1β and sgp-130 production. High doses of TBT also inhibited BDNF production. Conclusions TBT increases P4 but has minimal effect on downstream steroids. It enhances the production of inflammatory biomarkers such as IL-1β, TNF-α, IL-10 and IL-6. Inhibition of sgp-130 by TBT suggests that TBT may increase bioactive IL-6 production which has been associated with adverse neurodevelopmental outcomes. Reduced expression of BDNF also supports this possibility.

scholarly journals Shear stress modulates RAGE-mediated inflammation in a model of diabetes-induced metabolic stress

2012 ◽  
Vol 302 (12) ◽  
pp. H2498-H2508 ◽  
Author(s):  
J. Sherrod DeVerse ◽  
Keith A. Bailey ◽  
Kaleena N. Jackson ◽  
Anthony G. Passerini
Keyword(s):  
Shear Stress ◽  
Inflammatory Responses ◽  
Advanced Glycation Endproducts ◽  
Metabolic Stress ◽  
High Mobility ◽  
Dependent Manner ◽  
Direct Role ◽  
Arterial Hemodynamics ◽  
Tnf Α ◽  
Rage Expression

Atherosclerosis occurs preferentially at sites of disturbed blood flow despite the influence of risk factors contributing to systemic inflammation. The receptor for advanced glycation endproducts (RAGE) is a prominent mediator of inflammation in diabetes that is upregulated in atherosclerotic plaques. Our goal was to elucidate a role for arterial hemodynamics in the regulation of RAGE expression and activity. Endothelial RAGE expression was elevated at sites of flow disturbance in the aortas of healthy swine. To demonstrate a direct role for physiological shear stress (SS) in modulating RAGE expression, human aortic endothelial cells (HAEC) were exposed to high SS (HSS; 15 dyn/cm2), which downregulated RAGE by fourfold, or oscillatory SS (OSS; 0 ± 5 dyn/cm2), which upregulated RAGE by threefold, compared with static culture at 4 h. In a model of diabetes-induced metabolic stress, HAEC were chronically conditioned under high glucose (25 mM) and then simultaneously stimulated with TNF-α (0.5 ng/ml) and the RAGE ligand high mobility group box 1 (HMGB1). A 50% increase in VCAM-1 expression over TNF-α was associated with increased cytoplasmic and mitochondrial reactive oxygen species and NF-κB activity. This increase was RAGE-specific and NADPH oxidase dependent. In activated HAEC, OSS amplified HMGB1-induced VCAM-1 (3-fold) and RAGE (1.6-fold) expression and proportionally enhanced monocyte adhesion to HAEC in a RAGE-dependent manner, while HSS mitigated these increases to the level of TNF-α alone. We demonstrate that SS plays a fundamental role in regulating RAGE expression and inflammatory responses in the endothelium. These findings may provide mechanistic insight into how diabetes accelerates the nonrandom distribution of atherosclerosis in arteries.

scholarly journals The Multiple Roles of Cyk1p in the Assembly and Function of the Actomyosin Ring in Budding Yeast

1999 ◽  
Vol 10 (2) ◽  
pp. 283-296 ◽  
Author(s):  
Katie B. Shannon ◽  
Rong Li
Keyword(s):  
Actin Filaments ◽  
Fluorescent Protein ◽  
Budding Yeast ◽  
Dependent Manner ◽  
Size Change ◽  
Direct Role ◽  
Dynamic Component ◽  
Amino Terminal ◽  
Ring Assembly

The budding yeast IQGAP-like protein Cyk1p/Iqg1p localizes to the mother-bud junction during anaphase and has been shown to be required for the completion of cytokinesis. In this study, video microscopy analysis of cells expressing green fluorescent protein-tagged Cyk1p/Iqg1p demonstrates that Cyk1p/Iqg1p is a dynamic component of the contractile ring during cytokinesis. Furthermore, in the absence of Cyk1p/Iqg1p, myosin II fails to undergo the contraction-like size change at the end of mitosis. To understand the mechanistic role of Cyk1p/Iqg1p in actomyosin ring assembly and dynamics, we have investigated the role of the structural domains that Cyk1p/Iqg1p shares with IQGAPs. An amino terminal portion containing the calponin homology domain binds to actin filaments and is required for the assembly of actin filaments to the ring. This result supports the hypothesis that Cyk1p/Iqg1p plays a direct role in F-actin recruitment. Deletion of the domain harboring the eight IQ motifs abolishes the localization of Cyk1p/Iqg1p to the bud neck, suggesting that Cyk1p/Iqg1p may be localized through interactions with a calmodulin-like protein. Interestingly, deletion of the COOH-terminal GTPase-activating protein-related domain does not affect Cyk1p/Iqg1p localization or actin recruitment to the ring but prevents actomyosin ring contraction. In vitro binding experiments show that Cyk1p/Iqg1p binds to calmodulin, Cmd1p, in a calcium-dependent manner, and to Tem1p, a small GTP-binding protein previously found to be required for the completion of anaphase. These results demonstrate the critical function of Cyk1p/Iqg1p in regulating various steps of actomyosin ring assembly and cytokinesis.

New insights into the pathological role of TNF-α in early cardiac dysfunction and subsequent heart failure after infarction in rats

2004 ◽  
Vol 287 (1) ◽  
pp. H340-H350 ◽  
Author(s):  
C. Berthonneche ◽  
T. Sulpice ◽  
F. Boucher ◽  
L. Gouraud ◽  
J. de Leiris ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Function ◽  
Diastolic Pressure ◽  
Subsequent Development ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Direct Role ◽  
Volume Curve ◽  
Tnf Α

A marked increase in plasma TNF-α has been described in patients with chronic heart failure (CHF). Nevertheless, little is known about the direct role of this cytokine early after myocardial infarction (MI) and its possible effects on the subsequent development of CHF. Wistar rats were subjected to permanent in vivo coronary artery ligation. At 5, 7, and 9 days after MI, cardiac function, passive compliance of the left ventricle (LV), and cardiac geometry were evaluated. The same model was used to perform pharmacological studies 7 days and 10 wk after MI in rats treated with monomeric recombinant human soluble TNF-α receptor type II (sTNF-RII, 40 μg/kg iv) or a placebo on day 3. Maximal alterations of cardiac function and geometry occurred 7 days after MI, which correlated chronologically with a peak of cardiac and serum TNF-α, as shown by immunohistochemistry and ELISA, respectively. sTNF-RII improved LV end-diastolic pressure under basal conditions and after volume overload 7 days and 10 wk after MI. Moreover, a significant leftward shift of the pressure-volume curve in the sTNF-RII-treated group 7 days after MI indicated a preservation of LV volume. Infarct expansion index was also significantly improved by sTNF-RII 7 days after MI ( P < 0.01). Nevertheless, 10 wk after MI, geometric indexes and passive pressure-volume curves were not significantly improved by the treatment. In conclusion, TNF-α plays a major role in cardiac alterations 7 days after MI in rats and contributes to hemodynamic derangement, but not to cardiac remodeling, in subsequent CHF.

scholarly journals A type VII secretion system in Group B Streptococcus mediates cytotoxicity and virulence

2021 ◽  
Vol 17 (12) ◽  
pp. e1010121
Author(s):  
Brady L. Spencer ◽  
Uday Tak ◽  
Jéssica C. Mendonça ◽  
Prescilla E. Nagao ◽  
Michael Niederweis ◽  
...  
Keyword(s):  
Group B Streptococcus ◽  
Bioinformatic Analysis ◽  
Effector Proteins ◽  
Dependent Manner ◽  
Secretion Systems ◽  
Gram Positive Bacteria ◽  
Type Vii Secretion ◽  
Type Vii Secretion System ◽  
Group B

Type VII secretion systems (T7SS) have been identified in Actinobacteria and Firmicutes and have been shown to secrete effector proteins with functions in virulence, host toxicity, and/or interbacterial killing in a few genera. Bioinformatic analysis indicates that isolates of Group B Streptococcus (GBS) encode at least four distinct subtypes of T7SS machinery, three of which encode adjacent putative T7SS effectors with WXG and LXG motifs. However, the function of T7SS in GBS pathogenesis is unknown. Here we assessed the role of the most abundant GBS T7SS subtype during GBS pathogenesis. In a murine model of hematogenous meningitis, mice infected with GBS lacking a functional T7SS or lacking the secreted WXG100 effector EsxA exhibited less mortality, lower bacterial burdens in tissues, and decreased inflammation in the brain compared to mice infected with the parental GBS strain. We further showed that this T7SS induces cytotoxicity in brain endothelium and that EsxA contributes to these cytotoxicity phenotypes in a WXG motif-dependent manner. Finally, we determined that EsxA is a pore-forming protein, thus demonstrating the first role for a non-mycobacterial EsxA homolog in pore formation. This work reveals the importance of a T7SS in host–GBS interactions and has implications for T7SS effector function in other Gram-positive bacteria.

scholarly journals Up-regulation of BTLA expression in myeloid dendritic cells in neonatal sepsis associated with the treatment outcome and down-regulation of DC function

2020 ◽  
Author(s):  
Wandang Wang ◽  
Xuran Yang ◽  
Mingfa Guo ◽  
Zhifeng Pan ◽  
Mingjin Qiu ◽  
...  
Keyword(s):  
Neonatal Sepsis ◽  
Myeloid Dendritic Cells ◽  
Hla Dr ◽  
Tnf Α ◽  
Threatening Condition ◽  
Duration Of Hospitalization ◽  
Inflammatory Phenotype ◽  
Life Threatening ◽  
Antigen Presenting

Abstract Background: Neonatal sepsis is an acute life-threatening condition in neonates, and a proper innate inflammatory is essential for prevention of the systemic inflammation associated with sepsis. As the most potential antigen-presenting innate immune cells, dentritic cells (DCs) dysfunction has been verified detrimental for sepsis. B and T lymphocyte attenuator (BTLA) is an immune-regulatory receptor shown to be associated with DCs dysfunction. However, the role of BTLA expression in myeloid DCs (mDCs) in neonatal sepsis is unknown. Methods: 61 of neonates with sepsis and 32 of neonates having no suspicion of sepsis as control were enrolled into this study. BTLA and HLA-DR expression in mDCs was measured by flow cytometry. To further study the role of BTLA in regulating mDCs function, BTLA+mDCs and BTLA-mDCs from septic neonates were sorted and utilized to evaluate the phagacytosis capacity, bactericidal ability as well as cytokine secretion of mDCs.Results: A higher percentage of BTLA+mDCs were observed in neonatal septic patients and the percentage was positively correlated to the duration of hospitalization of neonates as well as the severity of sepsis. Moreover, a decrease MFI expression of HLA-DR was found in mDCs in neonatal sepsis, which expression was negatively correlated with the percentage of BTLA+mDCs. When compared to BTLA-mDCs, sorted BTLA+mDCs exhibited lower FITC-dextran uptake capacity but more CFU E.coli number after cells challenged by E.coli. In addition, BTLA+mDCs comparatively secreted lower level of TNF-α and IL-12, but higher IL-10. Conclusions: A higher level of BTLA in mDCs in the observed septic neonates was associated to the severity of neonatal sepsis; therefore, BTLA expression in mDCs could be a useful biomarker help to determine the neonatal sepsis development. Additionally, BTLA negatively regulated the phagocytosis capacity and bactericidal ability of mDCs and lowered their antigen-presenting ability as well as altered cells into an anti-inflammatory phenotype. Thus, targeting BTLA in mDCs may be a new therapeutic strategy for neonatal sepsis.

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