scholarly journals CpG-ODN Induces a Dose-Dependent Enrichment of Immunological Niches in the Spleen and Lungs of Neonatal Chicks That Correlates with the Protective Immunity against Escherichia coli

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Thushari Gunawardana ◽  
Khawaja Ashfaque Ahmed ◽  
Kalhari Goonewardene ◽  
Shelly Popowich ◽  
Shanika Kurukulasuriya ◽  
...  
Keyword(s):  
Immune Cell ◽  
Virulent Strain ◽  
T Cell Subsets ◽  
Dependent Manner ◽  
Cpg Odn ◽  
In Ovo ◽  
Protective Mechanisms ◽  
E Coli ◽  
Neonatal Chicks ◽  
Dose Dependent

Immunoprotective function of oligodeoxynucleotides containing CpG motifs (CpG-ODN) has been demonstrated in neonatal chickens against common bacterial pathogens such as E.coli and Salmonella sp. Our recent study reported that CpG-ODN administration enriches immune compartments in neonatal chicks. However, a causal relationship between CpG-ODN-induced immune enrichment and protective mechanisms remains unestablished. In this study, we investigated in ovo administered CpG-ODN-mediated immune cell recruitment in the immunological niches in lymphoid (spleen) and nonlymphoid (lungs) organs using various doses of CpG-ODN and examined whether the immunological profiles have any correlation with immunoprotection against E.coli infection. Eighteen-day-old embryonated eggs were injected with either 5, 10, 25, and 50 μg of CpG-ODN or saline (n=~40 per group). On the day of hatch (72 hr after CpG-ODN treatment), we collected the spleen and lungs (n=3‐4 per group) and examined the recruitment of macrophages/monocytes, their expression of MHCII and CD40, and the number of CD4+ and CD8+ T-cell subsets in the immunological niches in the spleen and lungs using flow cytometry. We observed the dose-dependent recruitment of immune cells, wherein 25 μg and 50 μg of CpG-ODN induced significant enrichment of immunological niches in both the spleen and the lungs. Four days after the CpG-ODN treatment (1-day after hatch), chicks were challenged with a virulent strain of E. coli (1×104 or 1×105 cfu, subcutaneously). Clinical outcome and mortality were monitored for 8 days postchallenge. We found that both 25 μg and 50 μg of CpG-ODN provided significant protection and reduced clinical scores compared to saline controls against E. coli infection. Overall, the present study revealed that CpG-ODNs orchestrate immunological niches in neonatal chickens in a dose-dependent manner that resulted in differential protection against E. coli infection, thus supporting a cause and effect relationship between CpG-ODN-induced immune enrichment and the antibacterial immunity.

scholarly journals The Antiinfective Effects of Velvet Antler of Formosan Sambar Deer (Cervus unicolor swinhoei) onStaphylococcus aureus-Infected Mice

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Ting-Yeu Dai ◽  
Chih-Hua Wang ◽  
Kun-Nan Chen ◽  
I-Nung Huang ◽  
Wei-Sheng Hong ◽  
...  
Keyword(s):  
Lipoteichoic Acid ◽  
Lavage Fluid ◽  
Dependent Manner ◽  
Protective Mechanisms ◽  
Velvet Antler ◽  
Sambar Deer ◽  
Dose Dependent ◽  
Cervus Unicolor

We assayed the effects of velvet antler (VA) of Formosan sambar deer (Cervus unicolor swinhoei) and its extracts on the anti-infective activity against pathogenicStaphylococcus aureus in vitroandin vivoin this study.In vitrodata indicated that the VA extracts stimulated the proliferation of resting splenocytes and macrophages in a dose-dependent manner up to the highest concentration used (150 μg mL−1). The production of proinflammatory cytokines (TNF-α, IL-6, IL-12) by lipoteichoic acid was significantly suppressed after being cocultured with the VA extracts in a dose-dependent manner. Animal test inS. aureus-infected mice demonstrated that the numbers of bacteria determined in the kidneys and peritoneal lavage fluid ofS. aureus-infected mice were significantly higher than those found in the same organs of mice pretreated with the VA samples. Moreover, the highly enhanced phagocytic activity of macrophages was further verified afterin vitrotreatment with the VA samples. The protective mechanisms of the VA samples might include an immune enhancer and an inflammatory cytokine suppressor.

scholarly journals Use of a model to understand the synergies underlying the antibacterial mechanism of H2O2-producing honeys

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Maria Masoura ◽  
Paolo Passaretti ◽  
Tim W. Overton ◽  
Pete A. Lund ◽  
Konstantinos Gkatzionis
Keyword(s):  
Gluconic Acid ◽  
Morphological Changes ◽  
Dependent Manner ◽  
Antibacterial Mechanism ◽  
General Stress Response ◽  
E Coli ◽  
Simple Model System ◽  
Ancient Times ◽  
K 12 ◽  
Dose Dependent

Abstract Honey has been valued as a powerful antimicrobial since ancient times. However, the understanding of the underlying antibacterial mechanism is incomplete. The complexity and variability of honey composition represent a challenge to this scope. In this study, a simple model system was used to investigate the antibacterial effect of, and possible synergies between, the three main stressors present in honey: sugars, gluconic acid, and hydrogen peroxide (H2O2), which result from the enzymatic conversion of glucose on honey dilution. Our results demonstrated that the synergy of H2O2 and gluconic acid is essential for the antibacterial activity of honey. This synergy caused membrane depolarization, destruction of the cell wall, and eventually growth inhibition of E. coli K-12. The presence of H2O2 stimulated the generation of other long-lived ROS in a dose-dependent manner. Sugars caused osmosis-related morphological changes, however, decreased the toxicity of the H2O2/gluconic acid. The susceptibility of catalase and general stress response sigma factor mutants confirmed the synergy of the three stressors, which is enhanced at higher H2O2 concentrations. By monitoring cellular phenotypic changes caused by model honey, we explained how this can be bactericidal even though the antimicrobial compounds which it contains are at non-inhibitory concentrations.

scholarly journals Simonkolleite Coating on Poly(Amino Acids) to Improve Osteogenesis and Suppress Osteoclast Formation in Vitro

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1505 ◽  
Author(s):  
Shuyang Li ◽  
Xingtao Chen ◽  
Xiaomei Wang ◽  
Yi Xiong ◽  
Yonggang Yan ◽  
...  
Keyword(s):  
Amino Acids ◽  
Osteoclast Formation ◽  
Mouse Bone Marrow ◽  
Graft Material ◽  
Dependent Manner ◽  
E Coli ◽  
Ft Ir ◽  
Dose Dependent ◽  
Relative Cell Viability

Zinc can enhance osteoblastic bone formation and stimulate osteogenic differentiation, suppress the differentiation of osteoclast precursor cells into osteoclasts, and inhibit pathogenic bacterial growth in a dose-dependent manner. In this study, simonkolleite, as a novel zinc resource, was coated on poly (amino acids) (PAA) via suspending PAA powder in different concentrations of zinc chloride (ZnCl2) solution, and the simonkolleite-coated PAA (Zn–PAA) was characterized by SEM, XRD, FT-IR and XPS. Zinc ions were continuously released from the coating, and the release behavior was dependent on both the concentration of the ZnCl2 immersing solution and the type of soak solutions (SBF, PBS and DMEM). The Zn–PAA was cultured with mouse bone marrow stem cells (BMSCs) through TranswellTM plates, and the results indicated that the relative cell viability, alkaline phosphatase (ALP) activity and mineralization of BMSCs were significantly higher with Zn–PAA as compared to PAA. Moreover, the Zn–PAA was cultured with RAW264.7 cells, and the results suggested an inhibiting effect of Zn–PAA on the cell differentiation into osteoclasts. In addition, Zn–PAA exhibited an antibacterial activity against both S. aureus and E. coli. These findings suggest that simonkolleite coating with certain contents could promote osteogenesis, suppress osteoclast formation and inhibit bacteria, indicating a novel way of enhancing the functionality of synthetic bone graft material and identifying the underline principles for designing zinc-containing bone grafts.

scholarly journals Intracellular Free Iron and Its Potential Role in Ultrahigh-Pressure-Induced Inactivation of Escherichia coli

2012 ◽  
Vol 79 (2) ◽  
pp. 722-724 ◽  
Author(s):  
Yuan Yan ◽  
Joy G. Waite-Cusic ◽  
Periannan Kuppusamy ◽  
Ahmed E. Yousef
Keyword(s):  
Escherichia Coli ◽  
Iron Chelator ◽  
Ultrahigh Pressure ◽  
Dependent Manner ◽  
Paramagnetic Resonance ◽  
Free Iron ◽  
Content Type ◽  
E Coli ◽  
Electron Paramagnetic ◽  
Dose Dependent

ABSTRACTIntracellular free iron ofEscherichia coliwas determined by whole-cell electron paramagnetic resonance spectrometry. Ultrahigh pressure (UHP) increased both intracellular free iron and cell lethality in a pressure-dose-dependent manner. The iron chelator 2,2′-dipyridyl protected cells against UHP treatments. A mutation that produced iron overload conditions sensitizedE. colito UHP treatment.

44 Exploring the use of silver and diamond nanoparticles on sperm cell invitro and chicken embryo in ovo

2021 ◽  
Vol 33 (2) ◽  
pp. 129
Author(s):  
M. P. Thavhana ◽  
T. L. Nedambale ◽  
L. J. Shai ◽  
M. L. Mphaphathi
Keyword(s):  
Cell Viability ◽  
Chicken Embryo ◽  
Sperm Cell ◽  
Control Group ◽  
Dependent Manner ◽  
Ag Nps ◽  
In Ovo ◽  
Diamond Nanoparticles ◽  
Immune Related Genes ◽  
Dose Dependent

In poultry industry, chick viability is a crucial factor determining profitability from fertilized egg to placement at the farm. However, decreases in fertility and hatchability have been observed. Recently, there has been renewed interest in the use of silver nanoparticles (Ag-NPs) due to their antimicrobial properties and growth-promoting ability, and diamond nanoparticles (D-NPs) due to their biocompatibility properties. The aim of the study was to evaluate the effect of silver and diamond nanoparticles on chicken embryo oxidative status, biochemical indices, and expression of immune-related genes and on sperm cell viability. The experiment was conducted in Ross 308 chicken embryos and Ross 308 cockerels. One hundred and fifty fertilized eggs were divided randomly into 5 groups (5×30). Fertilized eggs were injected with 50 mg/L Ag-NPs at volumes of 100μL (group 1), 200μL (group 2) or 50 mg/L D-NPs at volumes of 100μL (group 3) or 200μL (group 4), or received no nanoparticles (control; group 5) and incubated at 37°C and 55% humidity for 20 days. Then, chicken blood was collected and centrifuged to evaluate alkaline phosphatase (ALP), alanine transaminase (ALT), lactate dehydrogenase (LDH), glucose, urea, and free haemoglobin. Chicken embryo liver was used to evaluate antioxidant capacity (TAC) and chicken embryo spleen was used to evaluate expression of the immune-related genes interleukin-1β (IL-1β), toll-like receptor (TLR)4, TLR2, and TLR15. Semen was randomly divided into 1 control and 8 treatment groups and treated with 50 mg/L Ag-NPs: group A (0.1ppm), group B (1ppm), group C (5ppm), group D (10ppm) or 50 mg/L D-NPs: group E (1ppm), group F (5ppm), group G (10ppm), and group H (20ppm). Sperm viability was analysed using prestoblue metabolic assay. Data were analysed using PROC in GLM procedure of SAS 2014 (SAS Institute Inc.). Decrease in sperm cell viability was recorded in a dose-dependent manner. Sperm cell viability decreased (P<0.005) as the concentration of Ag-NP or D-NP increased. Addition of 100μL of Ag-NPs increased the growth rate of chicken embryo but not 200μL of Ag-NPs or addition of D-NPs. Increases in ALP, ALT, LDH, glucose and urea enzyme were observed in a dose-dependent manner in both Ag-NPs and D-NPs. Addition of 50 mg/L Ag-NPs or 50 mg/L D-NPs increased (P<0.001) TAC of chicken embryo as the volume increased. Additions of 200μL of Ag-NPs, 100μL of D-NPs, and 200μL of D-NPs were haemolytic (P<0.001) but addition of 100μL of Ag-NPs was not. Additions of 100 or 200μL of Ag-NPs or 100μL of D-NPs downregulated IL-1β and 200μL of D-NPs upregulated IL-1β compared with the untreated control group. Additions of 100 or 200μL of Ag-NPs or 200μL of D-NPs induced expression of TLR4 and TLR15. Furthermore, addition of Ag-NPs did not result in expression of TLR2. We concluded that administration of 50 mg/L Ag-NPs and 50 mg/L D-NPs in ovo improve immune status and administration of 100μL of Ag-NPs improved the growth rate of chicken embryo. However, toxicity associated with 50 mg/L Ag-NPs and 50 mg/L D-NPs remains a concern and need to be addressed before use.

scholarly journals Does Curcumin Have a Role in the Interaction between Gut Microbiota and Schistosoma mansoni in Mice?

Pathogens ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 767
Author(s):  
Assmaa Anter ◽  
Mohamed Abd El-Ghany ◽  
Marwa Abou El Dahab ◽  
Noha Mahana
Keyword(s):  
Schistosoma Mansoni ◽  
Intestinal Microbiota ◽  
Bacterial Species ◽  
Therapeutic Effects ◽  
Dependent Manner ◽  
Pseudomonas Sp ◽  
E Coli ◽  
Predominant Species ◽  
The Impact ◽  
Dose Dependent

There is strong correlation between changes in abundance of specific bacterial species and several diseases including schistosomiasis. Several studies have described therapeutic effects of curcumin (CUR) which may arise from its regulative effects on intestinal microbiota. Thus, we examined the impact of CUR on the diversity of intestinal microbiota with/without infection by Schistosoma mansoni cercariae for 56 days. Enterobacteriaceae was dominating in a naive and S. mansoni infected mice group without CUR treatment, the most predominant species was Escherichia coli with relative density (R.D%) = 80.66% and the least one was Pseudomonas sp. (0.52%). The influence of CUR on murine microbiota composition was examined one week after oral administration of high (40) and low (20 mg/kg b.w.) CUR doses were administered three times, with two day intervals. CUR induced high variation in the Enterobacteriaceae family, characterized by a significant (p < 0.001) reduction in E. coli and asignificant (p < 0.001) increase in Pseudomonas sp. in both naïve and S. mansoni-infected mice, compared to untreated mice, in a dose-dependent manner. Additionally, our study showed the effects of high CUR doses on S. mansoni infection immunological and parasitological parameters. These data support CUR’s ability to promote Pseudomonas sp. known to produce schistosomicidal toxins and offset the sequelae of murine schistosomiasis.

scholarly journals P062 Dose-dependent differential effects of vedolizumab therapy on adhesion of regulatory and effector T cells

2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S165-S166
Author(s):  
E Becker ◽  
M Wiendl ◽  
A Schulz-Kuhnt ◽  
I Atreya ◽  
R Atreya ◽  
...  
Keyword(s):  
T Cell ◽  
Mouse Model ◽  
T Cell Subsets ◽  
Dependent Manner ◽  
Differential Effects ◽  
Preferential Binding ◽  
Exposure Levels ◽  
Differential Binding ◽  
Dose Dependent

Abstract Background Vedolizumab has emerged as an important pillar of treatment in inflammatory bowel disease (IBD). However, for unknown reasons, not all patients respond to therapy. Earlier clinical studies suggested decreased response rates in the highest compared with medium dosage groups. Interestingly, vedolizumab has been shown to inhibit the homing of both regulatory (Treg) and effector T (Teff) cells and previous data from our group suggested different effect sizes in both populations. Thus, we hypothesised that the non-linear exposure–efficacy correlation might be explained by dose-dependent differential effects of vedolizumab on Treg and Teff homing. Therefore, we studied functional effects of different vedolizumab exposure levels on Treg and Teff cell trafficking. Methods The α4β7 expression on different human T-cell subsets as well as the binding characteristics of vedolizumab to these cells at different exposure levels was analysed via flow cytometry. Functional effects of different vedolizumab concentrations on the adhesion of Tregs and Teffs to mucosal addressin cell adhesion molecule 1 (MAdCAM-1) were analysed using dynamic in vitro adhesion assays, transmigration assays and in vivo homing assays in a humanised mouse model. The in vivo binding of vedolizumab to Tregs and Teffs in patients receiving therapy was quantified and correlated with the corresponding serum levels. Results We found a preferential binding of vedolizumab to Tregs at an exposure with 0.4 µg/ml vedolizumab that shifted to a preferential binding to Teffs at an exposure with 10 µg/ml. Further increase of vedolizumab to 50 µg/ml led to equal binding to Tregs and Teffs (Figure 1). Consistently, at 10 µg/ml, dynamic adhesion of Tregs to MAdCAM-1 was increased compared with Teffs, but no difference was noted at 50 µg/ml. Additionally, a higher number of Treg compared with Teff cells were able to transmigrate in a MAdCAM-1-dependent manner at a concentration of 10 µg/ml vedolizumab. Preliminary data from homing experiments in a humanised mouse model and from IBD patients treated with vedolizumab support the notion that differential binding preferences depending on the exposure level can also be observed in vivo. Conclusion Our findings support a dose-dependent differential binding of vedolizumab to different T-cell subpopulations and suggest that an optimal ‘window’ of exposure exists, in which effects on Teffs predominate over Tregs. While offering a potential explanation for earlier findings in dose-ranging studies, our data might lay the basis for the establishment of individualised dose optimisation in IBD patients.

Cloning and expression of a functional rat liver D-β-hydroxybutyrate dehydrogenase-β-galactosidase fusion protein in Escherichia coli

1991 ◽  
Vol 69 (9) ◽  
pp. 670-673
Author(s):  
Sharon Churchill ◽  
Perry Churchill
Keyword(s):  
Escherichia Coli ◽  
Rat Liver ◽  
Polyclonal Antibodies ◽  
Cloning And Expression ◽  
Dependent Manner ◽  
Bacteriophage Λ ◽  
Expression Library ◽  
Expression Plasmid ◽  
E Coli ◽  
Dose Dependent

A rat liver bacteriophage λ expression library was probed using polyclonal antibodies raised to purified rat liver D-β-hydroxybutyrate dehydrogenase (BDH). A clone was selected that contained a 1.2-kb insert. The insert placed in an expression plasmid was utilized to transform Escherichia coli. These cells were shown to possess phosphatidylcholine-dependent BDH activity. Cells transformed with only the plasmid had no detectable BDH activity in the presence of phosphatidylcholine. The expressed activity in E. coli could be inhibited in a dose-dependent manner by BDH antiserum.Key words: D-β-hydroxybutyrate dehydrogenase, cloning, expression.

scholarly journals The Escherichia coli Common Pilus and the Bundle-Forming Pilus Act in Concert during the Formation of Localized Adherence by Enteropathogenic E. coli

2009 ◽  
Vol 191 (11) ◽  
pp. 3451-3461 ◽  
Author(s):  
Zeus Saldaña ◽  
Ayşen L. Erdem ◽  
Stephanie Schüller ◽  
Iruka N. Okeke ◽  
Mark Lucas ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Cultured Cells ◽  
Dependent Manner ◽  
Triple Mutant ◽  
E Coli ◽  
Accessory Factor ◽  
Isogenic Mutants ◽  
Dose Dependent ◽  
Background Expression

ABSTRACT Although the bundle-forming pilus (BFP) of enteropathogenic Escherichia coli (EPEC) mediates microcolony formation on epithelial cells, the adherence of BFP-deficient mutants is significantly abrogated, but the mutants are still adherent due to the presence of intimin and possibly other adhesins. In this study we investigated the contribution of the recently described E. coli common pilus (ECP) to the overall adherence properties of EPEC. We found that ECP and BFP structures can be simultaneously observed in the course (between zero time and 7 h during infection) of formation of localized adherence on cultured epithelial cells. These two pilus types colocalized at different levels of the microcolony topology, tethering the adhering bacteria. No evidence of BFP disappearance was found after prolonged infection. When expressed from a plasmid present in nonadherent E. coli HB101, ECP rendered this organism highly adherent at levels comparable to those of HB101 expressing the BFP. Purified ECP bound in a dose-dependent manner to epithelial cells, and the binding was blocked with anti-ECP antibodies, confirming that the pili possess adhesin properties. An ECP mutant showed only a modest reduction in adherence to cultured cells due to background expression levels of BFP and intimin. However, isogenic mutants not expressing EspA or BFP were significantly less adherent when the ecpA gene was also deleted. Furthermore, a ΔespA ΔecpA double mutant (unable to translocate Tir and to establish intimate adhesion) was at least 10-fold less adherent than the ΔespA and ΔecpA single mutants, even in the presence of BFP. A Δbfp ΔespA ΔecpA triple mutant showed the least adherence compared to the wild type and all the isogenic mutant strains tested, suggesting that ECP plays a synergistic role in adherence. Our data indicate that ECP is an accessory factor that, in association with BFP and other adhesins, contributes to the multifactorial complex interaction of EPEC with host epithelial cells.

scholarly journals Electrochemical Detection of Waterborne Bacteria Using Bi-Functional Magnetic Nanoparticle Conjugates

Biosensors ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 36
Author(s):  
Dharanivasan Gunasekaran ◽  
Yoram Gerchman ◽  
Sefi Vernick
Keyword(s):  
Electrochemical Detection ◽  
Electrochemical Method ◽  
Magnetic Nanoparticle ◽  
Specific Binding ◽  
Dependent Manner ◽  
Igg Antibody ◽  
E Coli ◽  
Amine Functionalized ◽  
Highly Sensitive ◽  
Dose Dependent

Detection of microbial contamination in water is imperative to ensure water quality. We have developed an electrochemical method for the detection of E. coli using bi-functional magnetic nanoparticle (MNP) conjugates. The bi-functional MNP conjugates were prepared by terminal-specific conjugation of anti-E. coli IgG antibody and the electroactive marker ferrocene. The bi-functional MNP conjugate possesses both E. coli-specific binding and electroactive properties, which were studied in detail. The conjugation efficiency of ferrocene and IgG antibodies with amine-functionalized MNPs was investigated. Square-wave voltammetry enabled the detection of E. coli concentrations ranging from 101–107 cells/mL in a dose-dependent manner, as ferrocene-specific current signals were inversely dependent on E. coli concentrations, completely suppressed at concentrations higher than 107 cells/mL. The developed electrochemical method is highly sensitive (10 cells/mL) and, coupled to magnetic separation, provides specific signals within 1h. Overall, the bi-functional conjugates serve as ideal candidates for electrochemical detection of waterborne bacteria. This approach can be applied for the detection of other bacteria and viruses.

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