scholarly journals Distinct Physiologic and Inflammatory Responses Elicited in Baboons after Challenge with Shiga Toxin Type 1 or 2 from Enterohemorrhagic Escherichia coli

2010 ◽  
Vol 78 (6) ◽  
pp. 2497-2504 ◽  
Author(s):  
D. J. Stearns-Kurosawa ◽  
Valta Collins ◽  
Scott Freeman ◽  
Vernon L. Tesh ◽  
Shinichiro Kurosawa
Keyword(s):  
Escherichia Coli ◽  
Nonhuman Primate ◽  
Shiga Toxin ◽  
Inflammatory Responses ◽  
The United States ◽  
Enterohemorrhagic Escherichia Coli ◽  
Dependent Manner ◽  
Necrosis Factor Alpha ◽  
Tnf Α

ABSTRACTShiga toxin-producingEscherichia coliis a principal source of regional outbreaks of bloody diarrhea and hemolytic-uremic syndrome in the United States and worldwide. Primary bacterial virulence factors are Shiga toxin types 1 and 2 (Stx1 and Stx2), and we performed parallel analyses of the pathophysiologies elicited by the toxins in nonhuman primate models to identify shared and unique consequences of the toxemias. After a single intravenous challenge with purified Stx1 or Stx2, baboons (Papio) developed thrombocytopenia, anemia, and acute renal failure with loss of glomerular function, in a dose-dependent manner. Differences in the timing and magnitude of physiologic responses were observed between the toxins. The animals were more sensitive to Stx2, with mortality at lower doses, but Stx2-induced renal injury and mortality were delayed 2 to 3 days compared to those after Stx1 challenge. Multiplex analyses of plasma inflammatory cytokines revealed similarities (macrophage chemoattractant protein 1 [MCP-1] and tumor necrosis factor alpha [TNF-α]) and differences (interleukin-6 [IL-6] and granulocyte colony-stimulating factor [G-CSF]) elicited by the toxins with respect to the mediator induced and timing of the responses. Neither toxin induced detectable levels of plasma TNF-α. To our knowledge, this is the first time that thein vivoconsequences of the toxins have been compared in a parallel and reproducible manner in nonhuman primates, and the data show similarities to patient observations. The availability of experimental nonhuman primate models for Stx toxemias provides a reproducible platform for testing antitoxin compounds and immunotherapeutics with outcome criteria that have clinical meaning.

scholarly journals Micrococcus luteus Teichuronic Acids Activate Human and Murine Monocytic Cells in a CD14- and Toll-Like Receptor 4-Dependent Manner

2001 ◽  
Vol 69 (4) ◽  
pp. 2025-2030 ◽  
Author(s):  
Shuhua Yang ◽  
Shunji Sugawara ◽  
Toshihiko Monodane ◽  
Masahiro Nishijima ◽  
Yoshiyuki Adachi ◽  
...  
Keyword(s):  
Lipid A ◽  
Micrococcus Luteus ◽  
Dependent Manner ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Necrosis Factor Alpha ◽  
Monocytic Cells ◽  
Tnf Α

ABSTRACT Teichuronic acid (TUA), a component of the cell walls of the gram-positive organism Micrococcus luteus (formerlyMicrococcus lysodeikticus), induced inflammatory cytokines in C3H/HeN mice but not in lipopolysaccharide (LPS)-resistant C3H/HeJ mice that have a defect in the Toll-like receptor 4 (TLR4) gene, both in vivo and in vitro, similarly to LPS (T. Monodane, Y. Kawabata, S. Yang, S. Hase, and H. Takada, J. Med. Microbiol. 50:4–12, 2001). In this study, we found that purified TUA (p-TUA) induced tumor necrosis factor alpha (TNF-α) in murine monocytic J774.1 cells but not in mutant LR-9 cells expressing membrane CD14 at a lower level than the parent J774.1 cells. The TNF-α-inducing activity of p-TUA in J774.1 cells was completely inhibited by anti-mouse CD14 monoclonal antibody (MAb). p-TUA also induced interleukin-8 (IL-8) in human monocytic THP-1 cells differentiated to macrophage-like cells expressing CD14. Anti-human CD14 MAb, anti-human TLR4 MAb, and synthetic lipid A precursor IVA, an LPS antagonist, almost completely inhibited the IL-8-inducing ability of p-TUA, as well as LPS, in the differentiated THP-1 cells. Reduced p-TUA did not exhibit any activities in J774.1 or THP-1 cells. These findings strongly suggested that M. luteus TUA activates murine and human monocytic cells in a CD14- and TLR4-dependent manner, similar to LPS.

scholarly journals Mycoplasma pneumoniae-Derived Lipopeptides Induce Acute Inflammatory Responses in the Lungs of Mice

2007 ◽  
Vol 76 (1) ◽  
pp. 270-277 ◽  
Author(s):  
Takashi Shimizu ◽  
Yutaka Kida ◽  
Koichi Kuwano
Keyword(s):  
Mycoplasma Pneumoniae ◽  
Inflammatory Responses ◽  
Lavage Fluid ◽  
Peritoneal Macrophages ◽  
Necrosis Factor Alpha ◽  
Chemokine Production ◽  
Cytokines And Chemokines ◽  
Tnf Α ◽  
Mouse Peritoneal Macrophages

ABSTRACT The pathogenesis of Mycoplasma pneumoniae infection is considered to be in part attributable to excessive immune responses. In this study, we investigated whether synthetic lipopeptides of subunit b of F0F1-type ATPase (F0F1-ATPase), NF-κB-activating lipoprotein 1 (N-ALP1), and N-ALP2 (named FAM20, sN-ALP1, and sN-ALP2, respectively) derived from M. pneumoniae induce cytokine and chemokine production and leukocyte infiltration in vivo. Intranasal administration of FAM20 and sN-ALP2 induced infiltration of leukocyte cells and production of chemokines and cytokines in bronchoalveolar lavage fluid, but sN-ALP1 failed to do so. The activity of FAM20 was notably higher than that of sN-ALP2. FAM20 and sN-ALP2 induced tumor necrosis factor alpha (TNF-α) through Toll-like receptor 2 in mouse peritoneal macrophages. Moreover, in the range of low concentrations of lipopeptides, FAM20 showed relatively high activity of inducing TNF-α in mouse peritoneal macrophages compared to synthetic lipopeptides such as MALP-2 and FSL-1, derived from Mycoplasma fermentans and Mycoplasma salivarium, respectively. These findings indicate that the F0F1-ATPase might be a key molecule in inducing cytokines and chemokines contributing to inflammatory responses during M. pneumoniae infection in vivo.

scholarly journals Shiga Toxin Gene Loss and Transfer In Vitro and In Vivo during Enterohemorrhagic Escherichia coli O26 Infection in Humans

2007 ◽  
Vol 73 (10) ◽  
pp. 3144-3150 ◽  
Author(s):  
Martina Bielaszewska ◽  
Rita Prager ◽  
Robin Köck ◽  
Alexander Mellmann ◽  
Wenlan Zhang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Gene Loss ◽  
Pulsed Field Gel Electrophoresis ◽  
Enterohemorrhagic Escherichia Coli ◽  
Toxin Gene ◽  
Shiga Toxins ◽  
E Coli

ABSTRACT Escherichia coli serogroup O26 consists of enterohemorrhagic E. coli (EHEC) and atypical enteropathogenic E. coli (aEPEC). The former produces Shiga toxins (Stx), major determinants of EHEC pathogenicity, encoded by bacteriophages; the latter is Stx negative. We have isolated EHEC O26 from patient stools early in illness and aEPEC O26 from stools later in illness, and vice versa. Intrapatient EHEC and aEPEC isolates had quite similar pulsed-field gel electrophoresis (PFGE) patterns, suggesting that they might have arisen by conversion between the EHEC and aEPEC pathotypes during infection. To test this hypothesis, we asked whether EHEC O26 can lose stx genes and whether aEPEC O26 can be lysogenized with Stx-encoding phages from EHEC O26 in vitro. The stx 2 loss associated with the loss of Stx2-encoding phages occurred in 10% to 14% of colonies tested. Conversely, Stx2- and, to a lesser extent, Stx1-encoding bacteriophages from EHEC O26 lysogenized aEPEC O26 isolates, converting them to EHEC strains. In the lysogens and EHEC O26 donors, Stx2-converting bacteriophages integrated in yecE or wrbA. The loss and gain of Stx-converting bacteriophages diversifies PFGE patterns; this parallels findings of similar but not identical PFGE patterns in the intrapatient EHEC and aEPEC O26 isolates. EHEC O26 and aEPEC O26 thus exist as a dynamic system whose members undergo ephemeral interconversions via loss and gain of Stx-encoding phages to yield different pathotypes. The suggested occurrence of this process in the human intestine has diagnostic, clinical, epidemiological, and evolutionary implications.

Yogurt Containing Bioactive Molecules Produced by Lactobacillus acidophilus La-5 Exerts a Protective Effect against Enterohemorrhagic Escherichia coli in Mice

2012 ◽  
Vol 75 (10) ◽  
pp. 1796-1805 ◽  
Author(s):  
MOHAMED ZEINHOM ◽  
ANGELA M. TELLEZ ◽  
VERONIQUE DELCENSERIE ◽  
A. M. EL-KHOLY ◽  
S. H. EL-SHINAWY ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Protective Effect ◽  
Lactobacillus Acidophilus ◽  
Virulence Genes ◽  
Clinical Manifestations ◽  
Enterohemorrhagic Escherichia Coli ◽  
Bioactive Molecules ◽  
Necrosis Factor Alpha ◽  
In Vivo Effects

An active fraction extracted from Lactobacillus acidophilus La5 cell-free spent medium (LAla-5AF) was incorporated in a dairy matrix and tested to assess its antivirulent effect against enterohemorrhagic Escherichia coli (EHEC). Mice in experimental groups were fed for 4 days with yogurt supplemented with LAla-5AF. On the fifth day, mice were challenged with a single dose (107 CFU per mouse) of E. coli O157:H7. The clinical manifestations of the infection were significantly less severe in mice fed the yogurt supplemented with LAla-5AF. EHEC attachment and colonization was attenuated by LAla-5AF. Tumor necrosis factor alpha production was down-regulated, which might indicate a protective effect in the kidney during EHEC infection. To investigate the mechanisms associated with the in vivo effects observed, LAla-5AF was tested by reverse transcription real-time PCR to confirm its effects on the expression of several virulence genes of EHEC O157. The results showed that these fractions were able to down-regulate several virulence genes of EHEC, including stxB2, qseA, luxS, tir, ler, eaeA, and hlyB.

scholarly journals Suppression of Murine Endotoxin Response by E5531, a Novel Synthetic Lipid A Antagonist

1998 ◽  
Vol 42 (11) ◽  
pp. 2824-2829 ◽  
Author(s):  
Seiichi Kobayashi ◽  
Tsutomu Kawata ◽  
Akifumi Kimura ◽  
Kaname Miyamoto ◽  
Koichi Katayama ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Lipid A ◽  
Cell Surface Receptor ◽  
Dependent Manner ◽  
Necrosis Factor Alpha ◽  
In Vivo Models ◽  
Lps Challenge ◽  
Tnf Α

ABSTRACT As a consequence of blood-borne bacterial sepsis, endotoxin or lipopolysaccharide (LPS) from the cell walls of gram-negative bacteria can trigger an acute inflammatory response, leading to a series of pathological events and often resulting in death. To block this inflammatory response to endotoxin, a novel lipid A analogue, E5531, was designed and synthesized as an LPS antagonist, and its biological properties were examined in vitro and in vivo. In murine peritoneal macrophages, E5531 inhibited the release of tumor necrosis factor alpha (TNF-α) by Escherichia coli LPS with a 50% inhibitory concentration (IC50) of 2.2 nM, while E5531 elicited no significant increases in TNF-α on its own. In support of a mechanism consistent with antagonism of binding to a cell surface receptor for LPS, E5531 inhibited equilibrium binding of radioiodinated LPS ([125I]2-(r-azidosalicylamido)-1, 3′-dithiopropionate-LPS) to mouse macrophages with an IC50 of 0.50 μM. E5531 inhibited LPS-induced increases in TNF-α in vivo when it was coinjected with LPS into C57BL/6 mice primed with Mycobacterium bovis bacillus Calmette-Guérin (BCG). In this model, the efficacy of E5531 was inversely correlated to the LPS challenge dose, consistent with a competitive antagonist-like mechanism of action. Blockade of the inflammatory response by E5531 could further be demonstrated in other in vivo models: E5531 protected BCG-primed mice from LPS-induced lethality in a dose-dependent manner and suppressed LPS-induced hepatic injury in Propionibacterium acnes-primed or galactosamine-sensitized mice. These results argue that the novel synthetic lipid A analogue E5531 can antagonize the action of LPS in in vitro and suppress the pathological effects of LPS in vivo in mice.

scholarly journals Nonpathogenic Escherichia coli Strain Nissle 1917 Inhibits Signal Transduction in Intestinal Epithelial Cells

2007 ◽  
Vol 76 (1) ◽  
pp. 214-220 ◽  
Author(s):  
Nobuhiko Kamada ◽  
Kenichi Maeda ◽  
Nagamu Inoue ◽  
Tadakazu Hisamatsu ◽  
Susumu Okamoto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Nuclear Translocation ◽  
Inflammatory Responses ◽  
Epithelial Cell Line ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Anti Inflammatory ◽  
K 12 ◽  
Inflammatory Effect

ABSTRACT Although the probiotic Escherichia coli strain Nissle 1917 has been used for the treatment of inflammatory bowel diseases, the precise mechanisms of action of this strain remain unclear. In the present study, we estimated the anti-inflammatory effect of E. coli Nissle 1917 on inflammatory responses in vitro to determine the suppressive mechanism of Nissle 1917 on the inflammatory process. To determine the effect of E. coli Nissle 1917, the human colonic epithelial cell line HCT15 was incubated with or without E. coli Nissle 1917 or another nonpathogenic E. coli strain, K-12, and then tumor necrosis factor alpha (TNF-α)-induced interleukin-8 (IL-8) production from HCT15 cells was assessed. Enzyme-linked immunosorbent assays and real-time quantitative PCR showed that Nissle 1917 treatment suppressed TNF-α-induced IL-8 transcription and production. In addition, results from luciferase assays indicated that Nissle 1917 inhibited IL-8 promoter activity. On the other hand, these anti-inflammatory effects were not seen with E. coli K-12. In addition, heat-killed Nissle 1917 or its genomic DNA did not have this anti-inflammatory effect. Surprisingly, Nissle 1917 did not affect IL-8 transactivation pathways, such as NF-κB activation, nuclear translocation, and DNA binding, or even activation of other transcriptional factors. Furthermore, it also became evident that Nissle 1917 induced the anti-inflammatory effect without contact to epithelial cells. In conclusion, these data indicate that the nonpathogenic E. coli strain Nissle 1917 expresses a direct anti-inflammatory activity on human epithelial cells via a secreted factor which suppresses TNF-α-induced IL-8 transactivation through mechanisms different from NF-κB inhibition.

scholarly journals HOXA9 Participates in the Transcriptional Activation of E-Selectin in Endothelial Cells

2007 ◽  
Vol 27 (12) ◽  
pp. 4207-4216 ◽  
Author(s):  
Smarajit Bandyopadhyay ◽  
Mohammad Z. Ashraf ◽  
Pamela Daher ◽  
Philip H. Howe ◽  
Paul E. DiCorleto
Keyword(s):  
Transcriptional Activation ◽  
Leukocyte Adhesion ◽  
Regulatory Element ◽  
Proximal Region ◽  
Binding Motif ◽  
Dependent Manner ◽  
Necrosis Factor Alpha ◽  
Tnf Α

ABSTRACT The homeobox gene HOXA9 has recently been shown to be an important regulator of endothelial cell (EC) differentiation and activation in addition to its role in embryonic development and hematopoiesis. In this report, we have determined that the EC-leukocyte adhesion molecule E-selectin is a key target for HOXA9. The depletion of HOXA9 protein in ECs resulted in a significant and specific decrease in tumor necrosis factor alpha (TNF-α)-induced E-selectin gene expression. In addition, HOXA9 specifically activated the E-selectin gene promoter in ECs. Progressive deletional analyses together with site-specific mutagenesis of the E-selectin promoter indicated that the Abd-B-like HOX DNA-binding motif, CAATTTTATTAA, located in the proximal region spanning bp −210 to −221 upstream of the transcription start site was crucial for the promoter induction by HOXA9. Both HOXA9 in EC nuclear extract and recombinant HOXA9 protein bound to this sequence in vitro. Moreover, we showed that HOXA9 binds temporally, in a TNF-α-dependent manner, to the region containing this Abd-B-like element in vivo. We have thus identified a novel and functionally critical cis-regulatory element for TNF-α-mediated transient expression of the E-selectin gene. Further, we provide evidence that HOXA9 acts as an obligate proinflammatory factor by mediating cytokine induction of E-selectin.

scholarly journals Human Neutrophils and Their Products Induce Shiga Toxin Production by Enterohemorrhagic Escherichia coli

2001 ◽  
Vol 69 (3) ◽  
pp. 1934-1937 ◽  
Author(s):  
Patrick L. Wagner ◽  
David W. K. Acheson ◽  
Matthew K. Waldor
Keyword(s):  
Escherichia Coli ◽  
Clinical Isolate ◽  
Shiga Toxin ◽  
Toxin Production ◽  
Enterohemorrhagic Escherichia Coli ◽  
Human Neutrophils ◽  
Prophage Induction ◽  
Shiga Toxins ◽  
E Coli

ABSTRACT The Shiga toxins (Stx) are critical virulence factors forEscherichia coli O157:H7 and other serotypes of enterohemorrhagic E. coli (EHEC). These potent toxins are encoded in the genomes of temperate lambdoid bacteriophages. We recently demonstrated that induction of the resident Stx2-encoding prophage in an O157:H7 clinical isolate is required for toxin production by this strain. Since several factors produced by human cells, including hydrogen peroxide (H2O2), are capable of inducing lambdoid prophages, we hypothesized that such molecules might also induce toxin production by EHEC. Here, we studied whether H2O2 and also human neutrophils, an important endogenous source of H2O2, induced Stx2 expression by an EHEC clinical isolate. Both H2O2 and neutrophils were found to augment Stx2 production, raising the possibility that these agents may lead to prophage induction in vivo and thereby contribute to EHEC pathogenesis.

scholarly journals The Antimalarial Artemisinin Synergizes with Antibiotics To Protect against Lethal Live Escherichia coli Challenge by Decreasing Proinflammatory Cytokine Release

2006 ◽  
Vol 50 (7) ◽  
pp. 2420-2427 ◽  
Author(s):  
Jun Wang ◽  
Hong Zhou ◽  
Jiang Zheng ◽  
Juan Cheng ◽  
Wei Liu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Sensor Technology ◽  
Dependent Manner ◽  
Cpg Odn ◽  
Lethal Challenge ◽  
Necrosis Factor Alpha ◽  
E Coli ◽  
Tlr4 Mrna ◽  
Tnf Α ◽  
Anti Inflammatory

ABSTRACT In the present study artemisinin (ART) was found to have potent anti-inflammatory effects in animal models of sepsis induced by CpG-containing oligodeoxy-nucleotides (CpG ODN), lipopolysaccharide (LPS), heat-killed Escherichia coli 35218 or live E. coli. Furthermore, we found that ART protected mice from a lethal challenge by CpG ODN, LPS, or heat-killed E. coli in a dose-dependent manner and that the protection was related to a reduction in serum tumor necrosis factor alpha (TNF-α). More significantly, the administration of ART together with ampicillin or unasyn (a complex of ampicillin and sulbactam) decreased mortality from 100 to 66.7% or 33.3%, respectively, in mice subjected to a lethal live E. coli challenge. Together with the observation that ART alone does not inhibit bacterial growth, this result suggests that ART protection is achieved as a result of its anti-inflammatory activity rather than an antimicrobial effect. In RAW264.7 cells, pretreatment with ART potently inhibited TNF-α and interleukin-6 release induced by CpG ODN, LPS, or heat-killed E. coli in a dose- and time-dependent manner. Experiments utilizing affinity sensor technology revealed no direct binding of ART with CpG ODN or LPS. Flow cytometry further showed that ART did not alter binding of CpG ODN to cell surfaces or the internalization of CpG ODN. In addition, upregulated levels of TLR9 and TLR4 mRNA were not attenuated by ART treatment. ART treatment did, however, block the NF-κB activation induced by CpG ODN, LPS, or heat-killed E. coli. These findings provide compelling evidence that ART may be an important potential drug for sepsis treatment.

scholarly journals Chloroform Fraction ofCentratherum anthelminticum(L.) Seed Inhibits Tumor Necrosis Factor Alpha and Exhibits Pleotropic Bioactivities: Inhibitory Role in Human Tumor Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Aditya Arya ◽  
Mouna Achoui ◽  
Shiau-Chuen Cheah ◽  
Siddig Ibrahim Abdelwahab ◽  
Putri Narrima ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Human Tumor ◽  
Toxicity Testing ◽  
Antioxidant Property ◽  
Chloroform Fraction ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Mcf 7

We investigated the antioxidant potential, cytotoxic effect, and TNF-α inhibition activity with NF-κB activation response in a chloroform fraction ofCentratherum anthelminticumseeds (CACF). The antioxidant property of CACF was evaluated with DPPH, ORAC, and FRAP assays, which demonstrated significant antioxidant activity. The cytotoxicity of CACF was tested using the MTT assay; CACF effective inhibitory concentrations (IC50) for A549, PC-3, MCF-7, and WRL-68 cells were31.42±5.4,22.61±1.7,8.1±0.9, and54.93±8.3 μg/mL, respectively. CACF effectively and dose-dependently inhibited TNF-α release,in vitroandin vivo. CACF inhibited TNF-α secretion in stimulated RAW264.7 macrophage supernatants with an IC50of 0.012 μg/mL, without affecting their viability; the highest dose tested reduced serum TNF-α by 61%. Acute toxicity testing in rats revealed that CACF was non-toxic at all doses tested. Matching the cytotoxic activity towards a mechanistic approach, CACF dose-dependently exhibitedin vitroinhibitory effects against the activation of NF-κB translocation in MCF-7 cells. Preliminary phytochemical screening with GC/MS analysis detected 22 compounds in CACF, of which morpholinoethyl isothiocyanate was the most abundant (29.04%). The study reveals the potential of CACF in the treatment of breast cancer and in oxidative stress conditions with associated inflammatory responses.

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