scholarly journals Induction of Cytokine Synthesis by Flagella from Gram-Negative Bacteria May Be Dependent on the Activation or Differentiation State of Human Monocytes

1999 ◽  
Vol 67 (10) ◽  
pp. 5176-5185 ◽  
Author(s):  
Federica Ciacci-Woolwine ◽  
Patrick F. McDermott ◽  
Steven B. Mizel
Keyword(s):  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Substantial Effect ◽  
Gram Negative Bacteria ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Gram Negative ◽  
E Coli ◽  
Cytokine Synthesis ◽  
Normal Human Peripheral Blood

ABSTRACT We have previously demonstrated that salmonellae, but notEscherichia coli or Yersinia enterocolitica, stimulates tumor necrosis factor alpha (TNFα) production in the human promonocytic cell line U38. Subsequent analysis revealed that the TNFα-inducing activity of salmonellae was associated with flagellin, a major component of flagella from gram-negative bacteria. In the present study, we have explored the basis for the apparent specificity of action of Salmonella flagella on TNFα expression in U38 cells and have extended this analysis to normal human peripheral blood mononuclear cells (PBMC). Flagella from the enteropathogenicE. coli strain E2348/69, Y. enterocoliticaJB580, and Pseudomonas aeruginosa PAO1, which did not induce significant levels of TNFα production in U38 cells, were as potent as Salmonella flagella in terms of TNFα and interleukin 1β activation in PBMC. However, TNFα production in U38 cells was greatly enhanced when these cells were stimulated with flagella from E. coli, Y. enterocolitica, andP. aeruginosa in the presence of a costimulant, phorbol 13-myristate acetate. These findings are consistent with the hypothesis that the activation or differentiation state of a monocyte may have a substantial effect on the cell’s responsiveness to flagellum stimulation of cytokine synthesis. Furthermore, these results indicate that cytokine induction in monocytes may be a general property of flagella from gram-negative bacteria.

scholarly journals Effect of interleukin-1 (IL-1) blockade on cytokine synthesis: II. IL-1 receptor antagonist inhibits lipopolysaccharide-induced cytokine synthesis by human monocytes

Blood ◽  
1992 ◽  
Vol 79 (9) ◽  
pp. 2364-2369 ◽  
Author(s):  
EV Granowitz ◽  
E Vannier ◽  
DD Poutsiaka ◽  
CA Dinarello
Keyword(s):  
Receptor Antagonist ◽  
Messenger Rna ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Interleukin 1 ◽  
Tnf Alpha ◽  
Dependent Manner ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Cytokine Synthesis

Abstract Lipopolysaccharide (LPS) stimulates interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF alpha) gene expression and synthesis in human peripheral blood mononuclear cells (PBMC). IL-1 can also induce PBMC to synthesize IL-1 and TNF alpha. In the present study, we used IL- 1 receptor antagonist (IL-1ra) to determine the relative contribution of an IL-1-positive feedback loop to the total amount of LPS-induced cytokine synthesis. Pretreatment of PBMC with human recombinant IL-1ra reduced LPS-induced cytokine synthesis in a dose-dependent manner (P less than .001). Maximal inhibition was 33% for IL-1 alpha (P less than .01), 43% for IL-1 beta (P = .001), and 20% for TNF alpha (P less than .05). We consistently observed IL-1ra suppression of LPS-induced cytokines in PBMC of 38 volunteers. However, this phenomenon was not specific for LPS; 1 microgram/mL IL-1ra inhibited IL-1 beta synthesized in response to human recombinant IL-2 by 44% (P less than .001), toxic shock syndrome toxin-1 by 26% (P less than .05), and phorbol 12- myristate 13-acetate by 76% (P less than .001). IL-1ra added to PBMC 4 or 8 hours after stimulation with LPS still inhibited IL-1 beta synthesis by 44% (P less than .001) or 25% (P = .01), respectively. The steady state messenger RNA levels of IL-1 beta were reduced in PBMC stimulated by LPS in the presence of IL-1ra. In monocytes isolated by elutriation, IL-1ra reduced LPS-induced IL-1 alpha by 16% (P less than .001), IL-1 beta by 14% (P less than .05), and TNF alpha by 24% (P = .01). We conclude that IL-1-induced IL-1 significantly contributes to LPS-induced cytokine synthesis.

scholarly journals Effect of interleukin-1 (IL-1) blockade on cytokine synthesis: II. IL-1 receptor antagonist inhibits lipopolysaccharide-induced cytokine synthesis by human monocytes

Blood ◽  
1992 ◽  
Vol 79 (9) ◽  
pp. 2364-2369
Author(s):  
EV Granowitz ◽  
E Vannier ◽  
DD Poutsiaka ◽  
CA Dinarello
Keyword(s):  
Receptor Antagonist ◽  
Messenger Rna ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Interleukin 1 ◽  
Tnf Alpha ◽  
Dependent Manner ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Cytokine Synthesis

Lipopolysaccharide (LPS) stimulates interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF alpha) gene expression and synthesis in human peripheral blood mononuclear cells (PBMC). IL-1 can also induce PBMC to synthesize IL-1 and TNF alpha. In the present study, we used IL- 1 receptor antagonist (IL-1ra) to determine the relative contribution of an IL-1-positive feedback loop to the total amount of LPS-induced cytokine synthesis. Pretreatment of PBMC with human recombinant IL-1ra reduced LPS-induced cytokine synthesis in a dose-dependent manner (P less than .001). Maximal inhibition was 33% for IL-1 alpha (P less than .01), 43% for IL-1 beta (P = .001), and 20% for TNF alpha (P less than .05). We consistently observed IL-1ra suppression of LPS-induced cytokines in PBMC of 38 volunteers. However, this phenomenon was not specific for LPS; 1 microgram/mL IL-1ra inhibited IL-1 beta synthesized in response to human recombinant IL-2 by 44% (P less than .001), toxic shock syndrome toxin-1 by 26% (P less than .05), and phorbol 12- myristate 13-acetate by 76% (P less than .001). IL-1ra added to PBMC 4 or 8 hours after stimulation with LPS still inhibited IL-1 beta synthesis by 44% (P less than .001) or 25% (P = .01), respectively. The steady state messenger RNA levels of IL-1 beta were reduced in PBMC stimulated by LPS in the presence of IL-1ra. In monocytes isolated by elutriation, IL-1ra reduced LPS-induced IL-1 alpha by 16% (P less than .001), IL-1 beta by 14% (P less than .05), and TNF alpha by 24% (P = .01). We conclude that IL-1-induced IL-1 significantly contributes to LPS-induced cytokine synthesis.

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 Differential In Vitro Cytokine Induction by the Species of Cryptococcus gattii Complex

2018 ◽  
Vol 86 (4) ◽  
Author(s):  
Patricia F. Herkert ◽  
Jessica C. dos Santos ◽  
Ferry Hagen ◽  
Fatima Ribeiro-Dias ◽  
Flávio Queiroz-Telles ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Sensu Stricto ◽  
Cryptococcus Gattii ◽  
The Other ◽  
Human Pbmcs ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Tnf Α

ABSTRACT Cryptococcal species vary in capsule and cell size, thermotolerance, geographic distribution, and affected populations. Cryptococcus gattii sensu stricto and C. deuterogattii affect mainly immunocompetent hosts; however, C. bacillisporus , C. decagattii , and C. tetragattii cause infections mainly in immunocompromised hosts. This study aimed to compare the capacities of different species of the C. gattii species complex to induce cytokines and antimicrobial molecules in human peripheral blood mononuclear cells (PBMCs). Cryptococcus bacillisporus and C. deuterogattii induced the lowest levels of tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), and IL-6 among the five species of the C. gattii complex. Cryptococcus deuterogattii induced higher levels of IL-22 than those induced by C. tetragattii and the environmental species C. flavescens . In addition, C. bacillisporus and C. gattii sensu stricto proliferated inside human monocyte-derived macrophages after 24 h of infection. All Cryptococcus species were able to generate reactive oxygen species (ROS) in human PBMCs, with C. bacillisporus and C. deuterogattii being more efficient than the other species. In conclusion, C. bacillisporus and C. deuterogattii induce lower levels of the proinflammatory cytokines TNF-α, IL-1β, and IL-6 and higher ROS levels than those induced by the other species. Species of the Cryptococcus gattii complex have different abilities to induce cytokine and ROS production by human PBMCs.

scholarly journals Regulation of Transcription Factor E2-2 in Human Plasmacytoid Dendritic Cells by Monocyte-Derived TNFα

Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 162 ◽  
Author(s):  
Hannah K. Dewald ◽  
Harry J. Hurley ◽  
Patricia Fitzgerald-Bocarsly
Keyword(s):  
Dendritic Cells ◽  
Transcription Factor ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Plasmacytoid Dendritic Cells ◽  
Cytokine Signaling ◽  
Regulation Of Transcription ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Altered Expression

Plasmacytoid dendritic cells (pDCs) are innate immune cells and potent producers of interferon alpha (IFNα). Regulation of pDCs is crucial for prevention of aberrant IFN production. Transcription factor E2-2 (TCF4) regulates pDC development and function, but mechanisms of E2-2 control have not been investigated. We used freshly-isolated human peripheral blood mononuclear cells stimulated with toll-like receptor 7, 9, and 4 agonists to determine which factors regulate E2-2. After activation, pDCs decreased E2-2 expression. E2-2 downregulation occurred during the upregulation of costimulatory markers, after maximal IFN production. In congruence with previous reports in mice, we found that primary human pDCs that maintained high E2-2 levels produced more IFN, and had less expression of costimulatory markers. Stimulation of purified pDCs did not lead to E2-2 downregulation; therefore, we investigated if cytokine signaling regulates E2-2 expression. We found that tumor necrosis factor alpha (TNFα) produced by monocytes caused decreased E2-2 expression. All together, we established that primary human pDCs decrease E2-2 in response to TNFα and E2-2 low pDCs produce less IFN but exhibit more costimulatory molecules. Altered expression of E2-2 may represent a mechanism to attenuate IFN production and increase activation of the adaptive immune compartment.

Serum amyloid A is an innate immune opsonin for Gram-negative bacteria

Blood ◽  
2006 ◽  
Vol 108 (5) ◽  
pp. 1751-1757 ◽  
Author(s):  
Chandrabala Shah ◽  
Ranjeeta Hari-Dass ◽  
John G. Raynes
Keyword(s):  
Serum Amyloid A ◽  
Serum Amyloid ◽  
Reactive Oxygen Intermediate ◽  
Gram Negative Bacteria ◽  
Phagocytic Cells ◽  
Peripheral Blood Mononuclear ◽  
Gram Negative ◽  
E Coli ◽  
Amyloid A ◽  
Innate Recognition

Serum amyloid A (SAA) is the major acute-phase protein in man and most mammals. Recently we demonstrated that SAA binds to many Gram-negative bacteria including Escherichia coli and Pseudomonas aeruginosa through outer membrane protein A (OmpA) family members. Therefore we investigated whether SAA altered the response of innate phagocytic cells to bacteria. Both the percentage of neutrophils containing E coli and the number of bacteria per neutrophil were greatly increased by SAA opsonization, equivalent to the increase seen for serum opsonization. In contrast, no change was seen for Streptococcus pneumoniae, a bacteria that did not bind SAA. Neutrophil reactive oxygen intermediate production in response to bacteria was also increased by opsonization with SAA. SAA opsonization also increased phagocytosis of E coli by peripheral blood mononuclear cell-derived macrophages. These macrophages showed strong enhancement of TNF-α and IL-10 production in response to SAA-opsonized E coli and P aeruginosa. SAA did not enhance responses in the presence of bacteria to which it did not bind. These effects of SAA occur at normal concentrations consistent with SAA binding properties and a role in innate recognition. SAA therefore represents a novel innate recognition protein for Gram-negative bacteria.

Inhibition Of S100A6 Induces Graft Versus Leukemia Effects In MLL/AF4-Positive ALL In Human PBMC-SCID Mice

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2016-2016
Author(s):  
Hayato Tamai ◽  
Hiroki Yamaguchi ◽  
Kazuo Dan ◽  
Koiti Inokuchi
Keyword(s):  
Mononuclear Cells ◽  
Conflicts Of Interest ◽  
Human Peripheral Blood ◽  
Lymphoblastic Leukemia ◽  
Scid Mice ◽  
Long Term Effects ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Hematopoietic Stem ◽  
Graft Versus Leukemia

Mixed-lineage leukemia (MLL)/AF4-positive acute lymphoblastic leukemia (ALL) is associated with poor prognosis even after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The resistance to graft-versus-leukemia (GVL) effects may be responsible for the poor effect of allo-HSCT on MLL-AF4-positive ALL. Cytotoxic effector mechanisms mediated by tumor necrosis factor-alpha (TNF-a) was reported to contribute to the GVL effect. We reported previously that MLL/AF4-positive ALL shows resistance to TNF-a, which is the main factor in GVL effect, by upregulation of S100A6 expression followed by interference with the p53-caspase 8-caspase 3 pathway in vitro. We examined whether inhibition of S100A6 can induce an effective GVL effect on MLL/AF4-positive ALL in a mouse model. To examine the long-term effects of inhibition of S100A6,MLL/AF4-positive ALL cell lines (SEM) transduced with lentiviral vectors expressing both S100A6 siRNA and luciferase (SEM-Luc-S100A6 siRNA) were produced. SEM-Luc-S100A6 siRNA cells and SEM-Luc-control siRNA cells were injected into groups of five SCID mice (1×107/body). After confirmation of engraftment of SEM cells by in vivo imaging, the mice in each group were injected with 4.8×107 human peripheral blood mononuclear cells (PBMCs). Although there were no significant differences between the serum concentrations of human-TNF-a after injection of human PBMCs of SEM-Luc-S100A6 siRNA injected mice and those of SEM-Luc-control siRNA injected mice (P=0.95), SEM-Luc-S100A6 siRNA-injected mice showed significantly longer survival periods than SEM-Luc-control siRNA-injected mice (P = 0.002). SEM-Luc-S100A6 siRNA-injected mice showed significantly slower tumor growth than those injected with SEM-Luc-control siRNA (P < 0.0001). These results suggested that inhibition of S100A6 may be a promising therapeutic target for MLL/AF4-positive ALL in combination with allo-HSCT because it induce effective GVL effectson MLL/AF4-positive ALL which is resistant to GVL effects. Disclosures: No relevant conflicts of interest to declare.

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