Bacteriophage-Resistant Salmonella rissen: An In Vitro Mitigated Inflammatory Response

Non-typhoid Salmonella (NTS) represents one of the major causes of foodborne diseases, which are made worse by the increasing emergence of antibiotic resistance. Thus, NTS are a significant and common public health concern. The purpose of this study is to investigate whether selection for phage-resistance alters bacterial phenotype, making this approach suitable for candidate vaccine preparation. We therefore compared two strains of Salmonella enterica serovar Rissen: RR (the phage-resistant strain) and RW (the phage-sensitive strain) in order to investigate a potential cost associated with the bacterium virulence. We tested the ability of both RR and RW to infect phagocytic and non-phagocytic cell lines, the activity of virulence factors associated with the main Type-3 secretory system (T3SS), as well as the canonic inflammatory mediators. The mutant RR strain—compared to the wildtype RW strain—induced in the host a weaker innate immune response. We suggest that the mitigated inflammatory response very likely is due to structural modifications of the lipopolysaccharide (LPS). Our results indicate that phage-resistance might be exploited as a means for the development of LPS-based antibacterial vaccines.

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Ursodeoxycholic Acid (UDCA) Mitigates the Host Inflammatory Response during Clostridioides difficile Infection by Altering Gut Bile Acids

Infection and Immunity ◽

10.1128/iai.00045-20 ◽

2020 ◽

Vol 88 (6) ◽

Author(s):

Jenessa A. Winston ◽

Alissa J. Rivera ◽

Jingwei Cai ◽

Rajani Thanissery ◽

Stephanie A. Montgomery ◽

...

Keyword(s):

Immune Response ◽

Bile Acid ◽

Inflammatory Response ◽

Innate Immune Response ◽

Innate Immune ◽

Colonization Resistance ◽

Content Type ◽

Clostridioides Difficile

ABSTRACT Clostridioides difficile infection (CDI) is associated with increasing morbidity and mortality posing an urgent threat to public health. Recurrence of CDI after successful treatment with antibiotics is high, thus necessitating discovery of novel therapeutics against this enteric pathogen. Administration of the secondary bile acid ursodeoxycholic acid (UDCA; ursodiol) inhibits the life cycles of various strains of C. difficile in vitro, suggesting that the FDA-approved formulation of UDCA, known as ursodiol, may be able to restore colonization resistance against C. difficile in vivo. However, the mechanism(s) by which ursodiol is able to restore colonization resistance against C. difficile remains unknown. Here, we confirmed that ursodiol inhibits C. difficile R20291 spore germination and outgrowth, growth, and toxin activity in a dose-dependent manner in vitro. In a murine model of CDI, exogenous administration of ursodiol resulted in significant alterations in the bile acid metabolome with little to no changes in gut microbial community structure. Ursodiol pretreatment resulted in attenuation of CDI pathogenesis early in the course of disease, which coincided with alterations in the cecal and colonic inflammatory transcriptome, bile acid-activated receptors nuclear farnesoid X receptor (FXR) and transmembrane G-protein-coupled membrane receptor 5 (TGR5), which are able to modulate the innate immune response through signaling pathways such as NF-κB. Although ursodiol pretreatment did not result in a consistent decrease in the C. difficile life cycle in vivo, it was able to attenuate an overly robust inflammatory response that is detrimental to the host during CDI. Ursodiol remains a viable nonantibiotic treatment and/or prevention strategy against CDI. Likewise, modulation of the host innate immune response via bile acid-activated receptors FXR and TGR5 represents a new potential treatment strategy for patients with CDI.

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Stages of Meningococcal Sepsis Simulated In Vitro, with Emphasis on Complement and Toll-Like Receptor Activation

Infection and Immunity ◽

10.1128/iai.00195-08 ◽

2008 ◽

Vol 76 (9) ◽

pp. 4183-4189 ◽

Cited By ~ 32

Author(s):

Bernt Christian Hellerud ◽

Jørgen Stenvik ◽

Terje Espevik ◽

John D. Lambris ◽

Tom Eirik Mollnes ◽

...

Keyword(s):

Inflammatory Response ◽

Complement Activation ◽

Bacterial Load ◽

Receptor Activation ◽

Innate Immune ◽

Cytokine Secretion ◽

Hek293 Cells ◽

Toll Like Receptor ◽

Bacterial Concentration

ABSTRACT The clinical presentation of meningococcal disease is closely related to the number of meningococci in the circulation. This study aimed to examine the activation of the innate immune system after being exposed to increasing and clinically relevant concentrations of meningococci. We incubated representative Neisseria meningitidis serogroup B (ST-32) and serogroup C (ST-11) strains and a lipopolysaccharide (LPS)-deficient mutant (the 44/76 lpxA mutant) in human serum and whole blood and measured complement activation and cytokine secretion and the effect of blocking these systems. HEK293 cells transfected with Toll-like receptors (TLRs) were examined for activation of NF-κB. The threshold for cytokine secretion and activation of NF-κB was 103 to 104 meningococci/ml. LPS was the sole inflammation-inducing molecule at concentrations up to 105 to 106 meningococci/ml. The activation was dependent on TLR4-MD2-CD14. Complement contributed to the inflammatory response at ≥105 to 106 meningococci/ml, and complement activation increased exponentially at ≥107 bacteria/ml. Non-LPS components initiated TLR2-mediated activation at ≥107 bacteria/ml. As the bacterial concentration exceeded 107/ml, TLR4 and TLR2 were increasingly activated, independent of CD14. In this model mimicking human disease, the inflammatory response to N. meningitidis was closely associated with the bacterial concentration. Therapeutically, CD14 inhibition alone was most efficient at a low bacterial concentration, whereas addition of a complement inhibitor may be beneficial when the bacterial load increases.

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TLR3-mediated NF-κB signaling in human esophageal epithelial cells

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00065.2009 ◽

2009 ◽

Vol 297 (6) ◽

pp. G1172-G1180 ◽

Cited By ~ 39

Author(s):

Diana M. Lim ◽

Sneha Narasimhan ◽

Carmen Z. Michaylira ◽

Mei-Lun Wang

Keyword(s):

Immune Response ◽

Epithelial Cells ◽

Inflammatory Response ◽

Innate Immune Response ◽

Innate Immune ◽

Poly I:C ◽

Esophageal Epithelium ◽

Esophageal Epithelial Cells ◽

Stimulation Of

Despite its position at the front line against ingested pathogens, very little is presently known about the role of the esophageal epithelium in host innate immune defense. As a key player in the innate immune response, Toll-like receptor (TLR) signaling has not been well characterized in human esophageal epithelial cells. In the present study, we investigated the inflammatory response and signaling pathways activated by TLR stimulation of human esophageal cells in vitro. Using quantitative RT-PCR, we profiled the expression pattern of human TLRs 1–10 in primary esophageal keratinocytes (EPC2), immortalized nontransformed esophageal keratinocytes (EPC2-hTERT), and normal human esophageal mucosal biopsies and found that TLRs 1, 2, 3, and 5 were expressed both in vivo and in vitro. Using the cytokine IL-8 as a physiological read out of the inflammatory response, we found that TLR3 is the most functional of the expressed TLRs in both primary and immortalized esophageal epithelial cell lines in response to its synthetic ligand polyinosinic polycytidylic acid [poly(I:C)]. Through reporter gene studies, we show that poly(I:C)-induced NF-κB activation is critical for the transactivation of the IL-8 promoter in vitro and that nuclear translocation of NF-κB occurs at an early time point following poly(I:C) stimulation of esophageal epithelial cells. Importantly, we also show that poly(I:C) stimulation induces the NF-κB-dependent esophageal epithelial expression of TLR2, leading to enhanced epithelial responsiveness of EPC2-hTERT cells to TLR2 ligand stimulation, suggesting an important regulatory role for TLR3-mediated NF-κB signaling in the innate immune response of esophageal epithelial cells. Our findings demonstrate for the first time that TLR3 is highly functional in the human esophageal epithelium and that TLR3-mediated NF-κB signaling may play an important regulatory role in esophageal epithelial homeostasis.

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Unmetabolized quetiapine exerts an in vitro effect on innate immune cells by modulating inflammatory response and neutrophil extracellular trap formation

Biomedicine & Pharmacotherapy ◽

10.1016/j.biopha.2020.110497 ◽

2020 ◽

Vol 131 ◽

pp. 110497

Author(s):

Bárbara Osmarin Turra ◽

Fernanda Barbisan ◽

Verônica Farina Azzolin ◽

Cibele Ferreira Teixeira ◽

Thamara Flores ◽

...

Keyword(s):

Inflammatory Response ◽

Immune Cells ◽

Innate Immune ◽

Neutrophil Extracellular Trap ◽

Innate Immune Cells ◽

Trap Formation ◽

Extracellular Trap ◽

Vitro Effect

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Splenic sympathetic signaling contributes to acute neutrophil infiltration of the injured spinal cord

Journal of Neuroinflammation ◽

10.1186/s12974-020-01945-8 ◽

2020 ◽

Vol 17 (1) ◽

Author(s):

Susana Monteiro ◽

Andreia G. Pinho ◽

Mara Macieira ◽

Cláudia Serre-Miranda ◽

Jorge R. Cibrão ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Inflammatory Response ◽

Neutrophil Infiltration ◽

Innate Immune ◽

Injured Spinal Cord ◽

Post Injury ◽

Cord Injury ◽

Immune Changes

Abstract Background Alterations in the immune system are a complication of spinal cord injury (SCI) and have been linked to an excessive sympathetic outflow to lymphoid organs. Still unknown is whether these peripheral immune changes also contribute for the deleterious inflammatory response mounted at the injured spinal cord. Methods We analyzed different molecular outputs of the splenic sympathetic signaling for the first 24 h after a thoracic compression SCI. We also analyzed the effect of ablating the splenic sympathetic signaling to the innate immune and inflammatory response at the spleen and spinal cord 24 h after injury. Results We found that norepinephrine (NE) levels were already raised at this time-point. Low doses of NE stimulation of splenocytes in vitro mainly affected the neutrophils’ population promoting an increase in both frequency and numbers. Interestingly, the interruption of the sympathetic communication to the spleen, by ablating the splenic nerve, resulted in reduced frequencies and numbers of neutrophils both at the spleen and spinal cord 1 day post-injury. Conclusion Collectively, our data demonstrates that the splenic sympathetic signaling is involved in the infiltration of neutrophils after spinal cord injury. Our findings give new mechanistic insights into the dysfunctional regulation of the inflammatory response mounted at the injured spinal cord.

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Structural insight into autoinhibition of the NOD-like receptor NLRC4

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273314097599 ◽

2014 ◽

Vol 70 (a1) ◽

pp. C240-C240

Author(s):

Zehan Hu ◽

Jijie Chai

Keyword(s):

Large Family ◽

Innate Immune ◽

Secretion Systems ◽

Inhibitory Protein ◽

Danger Signals ◽

In Vitro Reconstitution ◽

Structural Insight ◽

Type 3 ◽

Insight Into

NOD-like receptor (NLR) proteins constitute a large family of intracellular innate immune receptors. NLRs respond to pathogen-derived signature components or host-derived danger signals, oligomerizing into multiprotein signaling complexes termed inflammasomes that catalyze caspase-1 activation. The NLRC4 (NLR family caspase-recruiting domain (CARD)-containing protein 4) inflammasome is activated by bacterial pathogens carrying the bacterial flagellin or the components of type 3 secretion systems. NAIP (NLR family, apoptosis inhibitory protein) family members dictate the specificity of the NLRC4 inflammasome for different bacterial ligands, with NAIP5/6 and NAIP2 directly recognizing the bacterial flagellin and the T3SS rod protein PrgJ in mice, respectively. We recently solved the crystal structure of NLRC4 in its auotinhibition form. In the current presentation, I discuss the NLRC4 autoinhibtion mechanism and its implications for autoinhbition of other NLR members. I also touch on in vitro reconstitution of the NLRC4 inflammasome and study of its Cryo-EM structure.

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Ursodeoxycholic acid (UDCA) mitigates the host inflammatory response during Clostridioides difficile infection by altering gut bile acids which attenuates NF-κB signaling via bile acid activated receptors

10.1101/2020.01.16.910018 ◽

2020 ◽

Author(s):

Jenessa A. Winston ◽

Alissa J. Rivera ◽

Jingwei Cai ◽

Rajani Thanissery ◽

Stephanie A. Montgomery ◽

...

Keyword(s):

Immune Response ◽

Bile Acid ◽

Inflammatory Response ◽

Ursodeoxycholic Acid ◽

Innate Immune Response ◽

Innate Immune ◽

Farnesoid X Receptor ◽

Clostridioides Difficile

AbstractClostridioides difficile infection (CDI) is associated with increasing morbidity and mortality posing an urgent threat to public health. Recurrence of CDI after successful treatment with antibiotics is high, thus necessitating discovery of novel therapeutics against this enteric pathogen. Administration of the secondary bile acid ursodeoxycholic acid (UDCA, ursodiol) inhibits the life cycle of various strains of C. difficile in vitro, suggesting the FDA approved formulation of UDCA, known as ursodiol, may be able to restore colonization resistance against C. difficile in vivo. However, the mechanism(s) by which ursodiol is able to restore colonization resistance against C. difficile remains unknown. Here, we confirmed that ursodiol inhibits C. difficile R20291 spore germination and outgrowth, growth, and toxin activity in a dose dependent manner in vitro. In a murine model of CDI, exogenous administration of ursodiol resulted in significant alterations in the bile acid metabolome with little to no changes in gut microbial community structure. Ursodiol pretreatment resulted in attenuation of CDI pathogenesis early in the course of disease, which coincided with alterations in the cecal and colonic inflammatory transcriptome, bile acid activated receptors nuclear farnesoid X receptor (FXR), and transmembrane G protein-coupled membrane receptor 5 (TGR5), which are able to modulate the innate immune response through signaling pathways such as NF-κB. Although ursodiol pretreatment did not result in a consistent decrease in the C. difficile life cycle in vivo, it was able to attenuate an overly robust inflammatory response that is detrimental to the host during CDI. Ursodiol remains a viable non-antibiotic treatment and/or prevention strategy against CDI. Likewise, modulation of the host innate immune response via bile acid activated receptors, FXR and TGR5, represents a new potential treatment strategy for patients with CDI.ImportanceThe clinical utility of ursodiol for prevention of recurrent CDI is currently in Phase 4 clinical trials. However, the mechanism by which ursodiol exerts its impacts on C. difficile pathogenesis is poorly understood. Herein, we demonstrated that ursodiol pretreatment attenuates CDI pathogenesis early in the course of disease in mice, which coincides with alterations in the cecal and colonic inflammatory transcriptome, bile acid activated receptors nuclear farnesoid X receptor (FXR), and transmembrane G protein-coupled membrane receptor 5 (TGR5), which are able to modulate the innate immune response through signaling pathways such as NF-κB. Ursodiol attenuated an overly robust inflammatory response that is detrimental to the host during CDI, and thus remains a viable non-antibiotic treatment and/or prevention strategy against CDI. Likewise, modulation of the host innate immune response via bile acid activated receptors, FXR and TGR5, represents a new potential treatment strategy for patients with CDI.AbbreviationsαMCA – α-Muricholic acid; βMCA –β-Muricholic acid; ωMCA –ω-Muricholic acid; CA – Cholic acid; CDCA – Chenodeoxycholic acid; DCA – Deoxycholic acid; GCDCA – Glycochenodeoxycholic acid; GDCA – Glycodeoxycholic acid; GLCA – Glycolithocholic acid; GUDCA – Glycoursodeoxycholic acid; HCA – Hyodeoxycholic acid; iDCA – Isodeoxycholic acid; iLCA – Isolithocholic acid; LCA – Lithocholic acid; TCA – Taurocholic acid; TCDCA – Taurochenodeoxycholic acid; TDCA – Taurodeoxycholic acid; THCA – Taurohyodeoxycholic acid; TUDCA – Tauroursodeoxycholic acid; TβMCA– Tauro-β-muricholic acid; TωMCA –Tauro ω-muricholic acid; UDCA Ursodeoxycholic acid.

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Inhibitory effects of epimedium herb water extract on the inflammatory response in vitro and in vivo

Planta Medica ◽

10.1055/s-0036-1596615 ◽

2016 ◽

Vol 81 (S 01) ◽

pp. S1-S381

Author(s):

YC Oh ◽

YH Jeong ◽

WK Cho ◽

SJ Lee ◽

JY Ma

Keyword(s):

Inflammatory Response ◽

Water Extract ◽

Inhibitory Effects

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Improvement of effectiveness in maize breeding

Acta Agronomica Hungarica ◽

10.1556/aagr.54.2006.3.10 ◽

2006 ◽

Vol 54 (3) ◽

pp. 351-358 ◽

Cited By ~ 2

Author(s):

P. Pepó

Keyword(s):

Recurrent Selection ◽

Genetic Manipulation ◽

Field Testing ◽

Tissue Cultures ◽

Maize Breeding ◽

Breeding Programmes ◽

Speed Up ◽

Selection For

Plant regeneration via tissue culture is becoming increasingly more common in monocots such as maize (Zea mays L.). Pollen (gametophytic) selection for resistance to aflatoxin in maize can greatly facilitate recurrent selection and the screening of germplasm for resistance at much less cost and in a shorter time than field testing. In vivo and in vitro techniques have been integrated in maize breeding programmes to obtain desirable agronomic attributes, enhance the genes responsible for them and speed up the breeding process. The efficiency of anther and tissue cultures in maize and wheat has reached the stage where they can be used in breeding programmes to some extent and many new cultivars produced by genetic manipulation have now reached the market.

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Bioactivity of Phenolic Compounds Extracted from Strawberry against Formation of Pseudomonas aeruginosa Biofilm

International Journal of Pharmaceutical Quality Assurance ◽

10.25258/ijpqa.10.1.27 ◽

2019 ◽

Vol 10 (01) ◽

Author(s):

Baydaa Hussein ◽

Zainab A. Aldhaher ◽

Shahrazad Najem Abdu-Allah ◽

Adel Hamdan

Keyword(s):

Pseudomonas Aeruginosa ◽

Phenolic Compounds ◽

Biofilm Formation ◽

Opportunistic Infections ◽

Formation Rate ◽

Hydrocarbon Chain ◽

Health Concern ◽

Gas Chromatography Mass Spectrometry ◽

Phenolic Contents

Background: Biofilm is a bacterial way of life prevalent in the world of microbes; in addition to that it is a source of alarm in the field of health concern. Pseudomonas aeruginosa is a pathogenic bacterium responsible for all opportunistic infections such as chronic and severe. Aim of this study: This paper aims to provide an overview of the promotion of isolates to produce a biofilm in vitro under special circumstances, to expose certain antibiotics to produce phenotypic evaluation of biofilm bacteria. Methods and Materials: Three diverse ways were used to inhibited biofilm formation of P.aeruginosa by effect of phenolic compounds extracts from strawberries. Isolates produced biofilm on agar MacConkey under certain circumstances. Results: The results showed that all isolates were resistant to antibiotics except sensitive to azithromycin (AZM, 15μg), and in this study was conducted on three ways to detect the biofilm produced, has been detected by the biofilm like Tissue culture plate (TCP), Tube method (TM), Congo Red Agar (CRA). These methods gave a clear result of these isolates under study. Active compounds were analyzed in both extracts by Gas Chromatography-mass Spectrometry which indicate High molecular weight compound with a long hydrocarbon chain. Conclusion: Phenolic compounds could behave as bioactive material and can be useful to be used in pharmaceutical synthesis. Phenolic contents which found in leaves and fruits extracts of strawberries shows antibacterial activity against all strains tested by the ability to reduce the production of biofilm formation rate.

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