scholarly journals Gamma Interferon Prevents the Inhibitory Effects of Oxidative Stress on Host Responses to Escherichia coliInfection

2001 ◽  
Vol 69 (4) ◽  
pp. 2621-2629 ◽  
Author(s):  
Michael J. Parmely ◽  
Fuan Wang ◽  
Douglas Wright
Keyword(s):  
Oxidative Stress ◽  
Bacterial Infections ◽  
Gamma Interferon ◽  
Glutathione Depletion ◽  
Intercellular Adhesion Molecule ◽  
Necrosis Factor Alpha ◽  
Gram Negative ◽  
E Coli ◽  
Redox Imbalance ◽  
Ifn Γ

ABSTRACT Oxidative stress occurs in animals challenged with bacterial endotoxin and can affect the expression of important host inflammatory genes. However, much less is known about the effects of oxidative stress on responses to gram-negative bacteria. The current study compared the effects of redox imbalance on hepatic responses of mice to Escherichia coli bacteria versus purified endotoxic lipopolysaccharide (LPS). Oxidative stress induced by glutathione depletion virtually eliminated hepatic tumor necrosis factor alpha responses to both E. coli and LPS. Inducible NO synthase (iNOS) and intercellular adhesion molecule-1 (ICAM-1) expression was also markedly inhibited by glutathione depletion in LPS-challenged mice, but was unaffected in E. coli-infected animals. Three findings suggested that gamma interferon (IFN-γ) production explained the differences between LPS and bacterial challenge. Glutathione depletion completely inhibited the IFN-γ response to LPS, but only partially inhibited IFN-γ production in infected mice. Exogenous IFN-γ restored iNOS and ICAM-1 responses to LPS in stressed mice. Conversely, IFN-γ-deficient, glutathione-depleted mice showed a marked decrease in iNOS and ICAM-1 expression when challenged with E. coli. These findings indicate that both the nature of the microbial challenge and the production of IFN-γ can be important in determining the effects of redox imbalance during gram-negative bacterial infections.

scholarly journals Gamma Interferon Production by Hepatic NK T Cells during Escherichia coli Infection Is Resistant to the Inhibitory Effects of Oxidative Stress

2003 ◽  
Vol 71 (5) ◽  
pp. 2468-2477 ◽  
Author(s):  
Guochi Zhang ◽  
Robert Dru Nichols ◽  
Masaru Taniguchi ◽  
Toshinori Nakayama ◽  
Michael J. Parmely
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Escherichia Coli ◽  
T Cells ◽  
Nk Cells ◽  
Inhibitory Effects ◽  
Gram Negative ◽  
E Coli ◽  
Nk T Cells ◽  
Ifn Γ

ABSTRACT The reductive-oxidative status of tissues regulates the expression of many inflammatory genes that are induced during gram-negative bacterial infections. The cytokine gamma interferon (IFN-γ) is a potent stimulus for host inflammatory gene expression, and oxidative stress has been shown to inhibit its production in mice challenged with Escherichia coli bacteria. The objective of the present study was to characterize the cells that produced IFN-γ in a mouse bacterial peritonitis model and determine the effects of oxidative stress on their activation. The liver contained large numbers of IFN-γ-expressing lymphocytes following challenge with viable E. coli bacteria. The surface phenotypes of IFN-γ-expressing hepatic lymphocytes were those of natural killer (NK) cells (NK1.1+ CD3−), conventional T cells (NK1.1− CD3+), and NK T cells (NK1.1+ CD3+). Treating mice with diethyl maleate to deplete tissue thiols significantly impaired IFN-γ production by NK cells, conventional T cells, and CD1d-restricted NK T cells in response to E. coli challenge. However, IFN-γ expression by a subset of NK T cells, which did not bind α-galactosylceramide-CD1d tetramers, was resistant to the inhibitory effects of tissue oxidative stress. Stress-resistant IFN-γ-expressing cells were also predominantly CD8+ and bore γδ T-cell antigen receptors. The residual IFN-γ response by NK T cells may explain previous reports of hepatic gene expression following gram-negative bacterial challenge in thiol-depleted mice. The finding also demonstrates that innate immune cells differ significantly in their responses to altered tissue redox status.

scholarly journals N-Formyl-Methionyl-Leucyl-Phenylalanine Inhibits both Gamma Interferon- and Interleukin-10-Induced Expression of FcγRI on Human Monocytes

2001 ◽  
Vol 8 (2) ◽  
pp. 402-408 ◽  
Author(s):  
Macarena Beigier-Bompadre ◽  
Paula Barrionuevo ◽  
Fernanda Alves-Rosa ◽  
Carolina J. Rubel ◽  
Marina S. Palermo ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Interleukin 10 ◽  
Inhibitory Effect ◽  
Gamma Interferon ◽  
Mononuclear Phagocytes ◽  
Human Neutrophils ◽  
Human Monocytes ◽  
Necrosis Factor Alpha ◽  
High Affinity Receptor ◽  
Ifn Γ

ABSTRACT Three different classes of receptors for the Fc portion of immunoglobulin G (FcγRs), FcγRI, FcγRII, and FcγRIII, have been identified on human leukocytes. One of them, FcγRI, is a high-affinity receptor capable of induction of functions that include phagocytosis, respiratory burst, antibody-dependent cell-mediated cytotoxicity (ADCC), and secretion of cytokines. This receptor is expressed on mononuclear phagocytes, and this expression is regulated by cytokines and hormones such as gamma interferon (IFN-γ), IFN-β, interleukin-10 (IL-10), and glucocorticoids. We have recently demonstrated that the chemotactic peptideN-formyl-methionyl-leucyl-phenylalanine (FMLP) is capable of inducing a time-dependent downregulation of both FcγRIIIB and FcγRII in human neutrophils, altering FcγR-dependent functions. Considering the biological relevance of the regulation of FcγRI, we investigated the effect of FMLP on the overexpression of FcγRI induced by both IFN-γ and IL-10 on human monocytes. We demonstrate that FMLP significantly abrogated IFN-γ- and IL-10-induced FcγRI expression, although its basal level of expression was not altered. However, other IFN-γ-mediated effects such as the overexpression of the major histocompatibility complex class II antigens and the enhancement of lipopolysaccharide-induced secretion of tumor necrosis factor alpha were not affected by FMLP treatment. The formyl peptide completely inhibited the IFN-γ- and IL-10-induced enhancement of ADCC and phagocytosis carried out by adherent cells. The inhibitory effect of FMLP on FcγRI upregulation could exert an important regulatory effect during the evolution of bacterial infections.

scholarly journals Interaction of Antimicrobial Peptide Temporin L with Lipopolysaccharide In Vitro and in Experimental Rat Models of Septic Shock Caused by Gram-Negative Bacteria

2006 ◽  
Vol 50 (7) ◽  
pp. 2478-2486 ◽  
Author(s):  
Andrea Giacometti ◽  
Oscar Cirioni ◽  
Roberto Ghiselli ◽  
Federico Mocchegiani ◽  
Fiorenza Orlando ◽  
...  
Keyword(s):  
Septic Shock ◽  
Antimicrobial Peptide ◽  
Gram Negative Bacteria ◽  
Amphibian Skin ◽  
Necrosis Factor Alpha ◽  
Gram Negative ◽  
Rat Models ◽  
E Coli ◽  
Tnf Α

ABSTRACT Sepsis remains a major cause of morbidity and mortality in hospitalized patients, despite intense efforts to improve survival. The primary lead for septic shock results from activation of host effector cells by endotoxin, the lipopolysaccharide (LPS) associated with cell membranes of gram-negative bacteria. For these reasons, the quest for compounds with antiendotoxin properties is actively pursued. We investigated the efficacy of the amphibian skin antimicrobial peptide temporin L in binding Escherichia coli LPS in vitro and counteracting its effects in vivo. Temporin L strongly bound to purified E. coli LPS and lipid A in vitro, as proven by fluorescent displacement assay, and readily penetrated into E. coli LPS monolayers. Furthermore, the killing activity of temporin L against E. coli was progressively inhibited by increasing concentrations of LPS added to the medium, further confirming the peptide's affinity for endotoxin. Antimicrobial assays showed that temporin L interacted synergistically with the clinically used β-lactam antibiotics piperacillin and imipenem. Therefore, we characterized the activity of temporin L when combined with imipenem and piperacillin in the prevention of lethality in two rat models of septic shock, measuring bacterial growth in blood and intra-abdominal fluid, endotoxin and tumor necrosis factor alpha (TNF-α) concentrations in plasma, and lethality. With respect to controls and single-drug treatments, the simultaneous administration of temporin L and β-lactams produced the highest antimicrobial activities and the strongest reduction in plasma endotoxin and TNF-α levels, resulting in the highest survival rates.

scholarly journals Gamma Interferon and Lipopolysaccharide Interact at the Level of Transcription To Induce Tumor Necrosis Factor Alpha Expression

2001 ◽  
Vol 69 (5) ◽  
pp. 2847-2852 ◽  
Author(s):  
Julia Y. Lee ◽  
Kathleen E. Sullivan
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Gamma Interferon ◽  
Necrosis Factor Alpha ◽  
Rnase Protection ◽  
Tnf Α ◽  
Factor Alpha ◽  
Ifn Γ ◽  
Necrosis Factor

ABSTRACT Lipopolysaccharide (LPS) is a very potent inducer of tumor necrosis factor alpha (TNF-α) expression from monocytes and macrophages. Another inflammatory cytokine, gamma interferon (IFN-γ), can potentiate the effects of LPS, but the mechanism is not thoroughly understood. Previous reports emphasized the ability of IFN-γ to upregulate CD14 expression (the receptor for LPS), and nearly all studies have utilized sequential stimulation with IFN-γ followed by LPS to exploit this phenomenon. This study demonstrates that IFN-γ can upregulate the effect of LPS at the level of transcription. Human monoblastic Mono-Mac-6 cells produced up to threefold-greater levels of TNF-α when simultaneously stimulated with LPS and IFN-γ compared to treatment with LPS alone. RNase protection studies showed a similar increase in RNA beginning as early as within 30 min. The synthesis of TNF-α mRNA in IFN-γ- and LPS-treated Mono-Mac-6 cells was also temporally prolonged even though the message turnover rate was identical to that seen in LPS stimulated cells. The modulatory effect of IFN-γ may be mediated by Jak2.

scholarly journals Bacteriological profile and antibiogram of cancer patients admitted in intensive care unit of a tertiary care cancer hospital in central Kerala

2020 ◽  
Vol 8 (12) ◽  
pp. 4450
Author(s):  
Sanjana Ramakrishnan ◽  
Sourabh Radhakrishnan ◽  
Sonu Lazar Cyriac
Keyword(s):  
Cancer Patients ◽  
Bacterial Infections ◽  
Tertiary Care ◽  
Gram Positive ◽  
Cross Sectional ◽  
Gram Negative ◽  
Mortality And Morbidity ◽  
E Coli ◽  
Resistance To Penicillin ◽  
Study Laboratory

Background: Opportunistic bacterial infections remain a serious morbidity among cancer patients. This study was aimed to determine the bacteriological and antibiotic profile of cancer patients admitted to the ICU of a tertiary care centre.Methods: Cross sectional study was done among cancer patients admitted in the Oncology neutropenic ICU during the period from August 2017 to July 2019. All patients admitted with a proven diagnosis of cancer for whom at least one bacterial culture was sent from any site were included in the study. Laboratory on culture reports were obtained from patient files and analysed.Results: A total of 278 samples from 256 patients (60±11.6 years) were analysed. Among the 111/278 positive cultures, 29 were blood samples and 1 was a pleural fluid sample. Gram negative organisms were 62.1% with Escherichia coli (25, 36.2%) as prevalent. Among the 37.8% gram positives, Staphylococcus aureus (18. 42.8%) was prevalent. Most of the E. coli strains showed highest resistance to ceftazidime (96%) and highest sensitivity to amikacin. The commonest gram-positive organism, Staphylococcus species were 100 % sensitive to vancomycin and linezolid and 100 % resistance to penicillin.  Conclusions: E. coli (gram negative) showed highest resistance to ceftazidime and sensitivity to amikacin. S. aureus (gram positive) was sensitive to vancomycin and linezolid and resistance to penicillin. An antibiogram for cancer patients helps the clinician to initiate an appropriate empirical antibiotic therapy to reduce mortality and morbidity.

scholarly journals Biochemical Evaluation of the Antioxidant Effects of Hydroxytyrosol on Pancreatitis-Associated Gut Injury

Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 781 ◽  
Author(s):  
Roberta Fusco ◽  
Marika Cordaro ◽  
Rosalba Siracusa ◽  
Ramona D’Amico ◽  
Tiziana Genovese ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Interleukin 1 ◽  
Antioxidant Properties ◽  
Pancreatic Tissue ◽  
Intercellular Adhesion Molecule ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Intercellular Adhesion Molecule 1 ◽  
Colon Tissue ◽  
Necrosis Factor Alpha

Acute pancreatitis is a severe abdominal pathology often associated with several complications including gut dysfunction. Oxidative stress is one of the most important pathways involved in this pathology. Hydroxytyrosol (HT), a phenolic compound obtained from olive oil, has shown anti-inflammatory and antioxidant properties. We evaluated the effects of HT administration on pancreatic and intestinal injury induced by caerulein administration. CD1 female mice were administered caerulein (50 μg/kg) for 10 h. HT treatment (5 mg/kg) was performed 30 min after the first caerulein injection and for two consecutive hours afterwards. One hour after the last caerulein injection, mice were sacrificed and serum, colon and pancreatic tissue samples were collected. HT was able to reduce the serum hallmarks of pancreatitis (amylase and lipase), histological damage score in both pancreas and colon tissue, inflammatory cells recruitment (mast cells) in both injured tissues, intrapancreatic trypsin activity and overexpression of the adhesion molecules (Intercellular Adhesion Molecule-1 (ICAM-1) and P-selectin) in colon. Additionally, HT reduced cytokine (interleukin 1 beta (IL- 1β), interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α)) levels in serum, pancreas and colon tissue and chemokine release (monocyte chemotactic protein-1 (MCP1/CCL2)) in pancreas and colon tissue. HT decreased lipid peroxidation and oxidative stress (superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST) activity) by enhancing the nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) in both injured tissues. Moreover, HT preserved intestinal barrier integrity, as shown by the diamine oxidase (DAO) serum levels and tight junction (zonula occludens (ZO) and occludin) expression in pancreas and colon. Our findings demonstrated that HT would be an important therapeutic tool against pancreatitis-induced injuries in the pancreas and gut.

scholarly journals Simultaneous Measurement of Antigen-Stimulated Interleukin-1β and Gamma Interferon Production Enhances Test Sensitivity for the Detection of Mycobacterium bovis Infection in Cattle

2010 ◽  
Vol 17 (12) ◽  
pp. 1946-1951 ◽  
Author(s):  
Gareth J. Jones ◽  
Chris Pirson ◽  
R. Glyn Hewinson ◽  
H. Martin Vordermeier
Keyword(s):  
Mycobacterium Bovis ◽  
Gamma Interferon ◽  
Interleukin 1Β ◽  
Induced Responses ◽  
Readout System ◽  
Necrosis Factor Alpha ◽  
Test Sensitivity ◽  
Inflammatory Protein ◽  
Tnf Α ◽  
Ifn Γ

ABSTRACT In order to identify cytokines that may be useful as candidates for inclusion in diagnostic tests for Mycobacterium bovis infection in cattle, we compared the levels of gamma interferon (IFN-γ), interleukin 1β (IL-1β), IL-4, IL-10, IL-12, macrophage inflammatory protein 1β (MIP-1β), and tumor necrosis factor alpha (TNF-α) in whole-blood cultures from tuberculosis (TB) reactor animals or TB-free controls following stimulation with M. bovis-specific antigens (purified protein derivative from M. bovis [PPD-B] or ESAT-6/CFP-10). In addition to IFN-γ responses, the production of IL-1β and TNF-α was also statistically significantly elevated in TB reactor cattle over that in uninfected controls following stimulation with PPD-B or ESAT-6/CFP-10 peptides. Thus, we evaluated whether the use of these two additional readouts could disclose further animals not detected by measuring IFN-γ alone. To this end, receiver operating characteristic (ROC) analyses were performed to define diagnostic cutoffs for positivity for TNF-α and IL-1β. These results revealed that for ESAT-6/CFP-10-induced responses, the use of all three readouts (IFN-γ, TNF-α, and IL-1β) in parallel increased the sensitivity of detection of M. bovis-infected animals by 11% but also resulted in a specificity decrease of 14%. However, applying only IFN-γ and IL-1β in parallel resulted in a 5% increase in sensitivity without the corresponding loss of specificity. The results for PPD-B-induced responses were similar, although the loss of specificity was more pronounced, even when only IFN-γ and IL-1β were used as readout systems. In conclusion, we have demonstrated that the use of an additional readout system, such as IL-1β, can potentially complement IFN-γ by increasing overall test sensitivity for the detection of M. bovis infection in cattle.

scholarly journals TNF-α and IFN-γ Participate in Improving the Immunoregulatory Capacity of Mesenchymal Stem/Stromal Cells: Importance of Cell–Cell Contact and Extracellular Vesicles

2021 ◽  
Vol 22 (17) ◽  
pp. 9531
Author(s):  
Lucero López-García ◽  
Marta Castro-Manrreza
Keyword(s):  
Immune Response ◽  
Extracellular Vesicles ◽  
Stromal Cells ◽  
Intercellular Adhesion Molecule ◽  
Cell Contact ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Ifn Γ ◽  
Immunoregulatory Mechanisms ◽  
Cell Cell

Mesenchymal stem/stromal cells (MSCs) have an immunoregulatory capacity and have been used in different clinical protocols requiring control of the immune response. However, variable results have been obtained, mainly due to the effect of the microenvironment on the induction, increase, and maintenance of MSC immunoregulatory mechanisms. In addition, the importance of cell–cell contact for MSCs to efficiently modulate the immune response has recently been highlighted. Because these interactions would be difficult to achieve in the physiological context, the release of extracellular vesicles (EVs) and their participation as intermediaries of communication between MSCs and immune cells becomes relevant. Therefore, this article focuses on analyzing immunoregulatory mechanisms mediated by cell contact, highlighting the importance of intercellular adhesion molecule-1 (ICAM-1) and the participation of EVs. Moreover, the effects of tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ), the main cytokines involved in MSC activation, are examined. These cytokines, when used at the appropriate concentrations and times, would promote increases in the expression of immunoregulatory molecules in the cell and allow the acquisition of EVs enriched with these molecules. The establishment of certain in vitro activation guidelines will facilitate the design of conditioning protocols to obtain functional MSCs or EVs in different pathophysiological conditions.

scholarly journals Age-Dependent Levels of Select Immunological Mediators in Sera of Healthy Children

1998 ◽  
Vol 5 (1) ◽  
pp. 28-32 ◽  
Author(s):  
Ulrich Sack ◽  
Ullrich Burkhardt ◽  
Michael Borte ◽  
Hiltrud Schädlich ◽  
Kerstin Berg ◽  
...  
Keyword(s):  
Interleukin 1 ◽  
Physical Growth ◽  
Intercellular Adhesion Molecule ◽  
Healthy Children ◽  
Intercellular Adhesion Molecule 1 ◽  
Necrosis Factor Alpha ◽  
Age Related ◽  
Tnf Α ◽  
Age Dependent ◽  
Ifn Γ

ABSTRACT Serum cytokine levels were measured in 275 healthy children of different ages (3 to 17 years). Interleukin-1 receptor antagonist (IL-1RA), soluble IL-2R (sIL-2R) (sCD25), IL-6, IL-8, tumor necrosis factor alpha (TNF-α), soluble TNF receptor type II (sTNF-RII) (sCD120b), gamma interferon (IFN-γ), soluble intercellular adhesion molecule 1 (sICAM-1) (sCD54), soluble E selectin (sE-selectin) (ELAM-1; sCD62E), sCD14, and neopterin were measured with commercial test kits. The mean levels of IL-1RA, sIL-2R, TNF-α, sICAM-1, sE-selectin, and sCD14 were higher than in healthy adults. In contrast, IFN-γ and IL-8 were hardly detectable in children and thereby significantly lower than in adults. In the case of TNF-α, sICAM-1, sE selectin, and sCD14, there was a high interindividual variability, apparently unrelated to disease. The profiles of some cytokines, i.e., IL-1RA, IL-6, and TNF-α, showed age-related increases that overlapped with known patterns of physical growth. Of note, sIL-2R and sE-selectin instead declined with time. Because of the remarkable age-dependent variability in healthy pediatric subjects, disease-related changes, as well as therapy-dependent alterations, should be considered with caution.

scholarly journals Mode of action of the 2-phenylquinoline efflux inhibitor PQQ4R againstEscherichia coli

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3168 ◽  
Author(s):  
Diana Machado ◽  
Laura Fernandes ◽  
Sofia S. Costa ◽  
Rolando Cannalire ◽  
Giuseppe Manfroni ◽  
...  
Keyword(s):  
Mode Of Action ◽  
Bacterial Infections ◽  
Efflux Pump ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Synergistic Activity ◽  
Dependent Manner ◽  
Gram Negative ◽  
E Coli ◽  
Efflux Pump Inhibitors

Efflux pump inhibitors are of great interest since their use as adjuvants of bacterial chemotherapy can increase the intracellular concentrations of the antibiotics and assist in the battle against the rising of antibiotic-resistant bacteria. In this work, we have described the mode of action of the 2-phenylquinoline efflux inhibitor (4-(2-(piperazin-1-yl)ethoxy)-2-(4-propoxyphenyl) quinolone – PQQ4R), againstEscherichia coli,by studding its efflux inhibitory ability, its synergistic activity in combination with antibiotics, and compared its effects with the inhibitors phenyl-arginine-β-naphthylamide (PAβN) and chlorpromazine (CPZ). The results showed that PQQ4R acts synergistically, in a concentration dependent manner, with antibiotics known to be subject to efflux inE. colireducing their MIC in correlation with the inhibition of their efflux. Real-time fluorometry assays demonstrated that PQQ4R at sub-inhibitory concentrations promote the intracellular accumulation of ethidium bromide inhibiting its efflux similarly to PAβN or CPZ, well-known and described efflux pump inhibitors for Gram-negative bacteria and whose clinical usage is limited by their levels of toxicity at clinical and bacteriological effective concentrations. The time-kill studies showed that PQQ4R, at bactericidal concentrations, has a rapid antimicrobial activity associated with a fast decrease of the intracellular ATP levels. The results also indicated that the mode of action of PQQ4R involves the destabilization of theE. coliinner membrane potential and ATP production impairment, ultimately leading to efflux pump inhibition by interference with the energy required by the efflux systems. At bactericidal concentrations, membrane permeabilization increases and finally ATP is totally depleted leading to cell death. Since drug resistance mediated by the activity of efflux pumps depends largely on the proton motive force (PMF), dissipaters of PMF such as PQQ4R, can be regarded as future adjuvants of conventional therapy againstE. coliand other Gram-negative bacteria, especially their multidrug resistant forms. Their major limitation is the high toxicity for human cells at the concentrations needed to be effective against bacteria. Their future molecular optimization to improve the efflux inhibitory properties and reduce relative toxicity will optimize their potential for clinical usage against multi-drug resistant bacterial infections due to efflux.

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