scholarly journals Mechanisms of Inflammasome Activation by Vibrio cholerae Secreted Toxins Vary with Strain Biotype

2015 ◽  
Vol 83 (6) ◽  
pp. 2496-2506 ◽  
Author(s):  
Jessica Queen ◽  
Shivani Agarwal ◽  
Jazel S. Dolores ◽  
Christian Stehlik ◽  
Karla J. F. Satchell
Keyword(s):  
Vibrio Cholerae ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Inflammasome Activation ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Peripheral Blood Mononuclear ◽  
Content Type ◽  
Murine Macrophages ◽  
El Tor

Activation of inflammasomes is an important aspect of innate immune responses to bacterial infection. Recent studies have linkedVibrio choleraesecreted toxins to inflammasome activation by using murine macrophages. To increase relevance to human infection, studies of inflammasome-dependent cytokine secretion were conducted with the human THP-1 monocytic cell line and corroborated in primary human peripheral blood mononuclear cells (PBMCs). Both El Tor and classical strains ofV. choleraeactivated ASC (apoptosis-associated speck-like protein-containing a CARD domain)-dependent release of interleukin-1β (IL-1β) when cultured with human THP-1 cells, but the pattern of induction was distinct, depending on the repertoire of toxins the strains produced. El Tor biotype strains induced release of IL-1β dependent on NOD-like receptor family pyrin domain-containing 3 (NLRP3) and ASC due to the secreted pore-forming toxin hemolysin. Unlike in studies with mouse macrophages, the MARTX toxin did not contribute to IL-1β release from human monocytic cells. Classical biotype strains, which do not produce either hemolysin or the MARTX toxin, activated low-level IL-1β release that was induced by cholera toxin (CT) and dependent on ASC but independent of NLRP3 and pyroptosis. El Tor strains likewise showed increased IL-1β production dependent on CT when the hemolysin gene was deleted. In contrast to studies with murine macrophages, this phenotype was dependent on a catalytically active CT A subunit capable of inducing production of cyclic AMP and not on the B subunit. These studies demonstrate that the induction of the inflammasome in human THP-1 monocytes and in PBMCs byV. choleraevaries with the biotype and is mediated by both NLRP3-dependent and -independent pathways.

scholarly journals Binding of gamma-glutamyl transferase to TLR-4 allows the activation of tissue factor expression in human monocytes

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
C Sanguinetti ◽  
V Scalise ◽  
T Neri ◽  
A Celi ◽  
R Pedrinelli
Keyword(s):  
Tissue Factor ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Gamma Glutamyl Transferase ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Peripheral Blood Mononuclear ◽  
Gamma Glutamyl ◽  
Increased Risk ◽  
Glutamyl Transferase

Abstract Background Gamma-glutamyl transferase (GGT) plays a key role in the antioxidant processes, however, it also exerts pro-oxidant effects by activating NFkB, a redox-sensitive transcription factor key in the induction of Tissue Factor (TF) gene expression, the initiator of the clotting cascade. GGT may modulate TF expression, an assumption verified by previous studies carried out in human Peripheral Blood Mononuclear Cells (PBMCs). Quite importantly, TF expression in response to GGT stimulation was independent of its enzymatic activity since those experiments were conducted by using human recombinant (hr)GGT, a wheat germ-derived protein enzymatically inert. Thus, GGT may act through a cytokine-like mechanism although the precise determinants of its action and the receptor involved were not defined by those experiments. Purpose To assess whether GGT-induced TF stimulation is a consequence of binding to Toll-Like Receptor (TLR)-4 and activation of NF-κB, as suggested by results recently obtained in different experimental contexts. Methods PBMCs obtained from healthy donors through a discontinuous Ficoll/Hystopaque density gradient and THP-1 cells, a human monocytic cell line derived from a leukemia patient, were incubated with hrGGT (0.5 ng/μl for PBMCs and 1ng/μl for THP-1). LPS-Rs (0.5 ng/μl for PBMCs and 1 ng/μl for THP-1), CLI-095 (3x10–6 M) and BAY-11-7082 (10–5 M) were used to block TLR-4 receptors, TLR4 signaling and NF-κB respectively. TF pro-coagulant activity (PCA) was assessed using of StartMax coagulometer and results were expressed in pg/ml after calibration with a standard curve. HEK-Blue hTLR4-positive and HEK-Blue hTLR4-negative cells are used to evaluate the engagement of TLR4 by hrGGT. Results hrGGT increased TF expression in both PBMCs (PCA from 110±70 to 510±43, n=7, p<0.01) and THP-1 cells (PCA from 170±64 to 460±80, n=15, p<0.001).In PBMCs GGT-induced TF stimulation was antagonized by LPS-Rs (PCA: −72±17% n=4, p<0.01) a TLR-4 antagonist, CLI-095 (PCA:-74±34%, n=7, p<0.001) a TLR-4 intracellular antagonist and BAY-11-7082 (PCA: −71±32%, n=7, p<0.001), a NF-κB inhibitor. Similar results were obtained in THP-1 cells [LPS-Rs: −76±15%, n=6, p<0.01; CLI-095: −100±6,6%, n=6, p<0.01; BAY-11-7082: −100±2,1%, n=6, p<0.01]. hrGGT activates NF-κB in hTLR4-positive HEK cell lines while doesn't induces effect in TLR4-negative HEK cells. Conclusions Besides confirming the cytokine-Like activity of GGT and its procoagulant effect in PBMCs and THP-1 cells, these data identify for the first time the possible role of TLR-4 as the receptor of GGT and NfkB as the involved signal transduction pathway. The GGT-TLR-4 link may provide an explanation to the association between circulating GGT levels and increased risk of acute thrombotic events as well as to the involvement of GGT in the morbid evolution of the atherosclerotic plaque in which GGT colocalizes with monocytes and foam cells, the prime sources of TF within the plaque. FUNDunding Acknowledgement Type of funding sources: None.

scholarly journals Evaluation of Immunostimulatory Activities of Synthetic Mannose-Containing Structures Mimicking the β-(1→2)-Linked Cell Wall Mannans of Candida albicans

2012 ◽  
Vol 19 (11) ◽  
pp. 1889-1893 ◽  
Author(s):  
Kaarina Ranta ◽  
Kaisa Nieminen ◽  
Filip S. Ekholm ◽  
Moniká Poláková ◽  
Mattias U. Roslund ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Peripheral Blood Mononuclear ◽  
Content Type ◽  
Mouse Macrophages ◽  
Ifn Γ ◽  
Low Levels ◽  
Necrosis Factor

ABSTRACTImmunostimulatory properties of synthetic structures mimicking the β-(1→2)-linked mannans ofCandida albicanswere evaluatedin vitro. Contrary to earlier observations, tumor necrosis factor (TNF) production was not detected after stimulation with mannotetraose in mouse macrophages. Divalent disaccharide 1,4-bis(α-d-mannopyranosyloxy)butane induced TNF and some molecules induced low levels of gamma interferon (IFN-γ) in human peripheral blood mononuclear cells (PBMC).

Abstract 447: β-cyclodextrin Reduces Cholesterol Crystal-induced Inflammation Through Modulating Complement Activation

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Terje Espevik ◽  
Siril S Bakke ◽  
Nathalie Niyonzima ◽  
Jan K Damås ◽  
Liv Ryan ◽  
...  
Keyword(s):  
Complement Activation ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Inflammasome Activation ◽  
Potential Candidate ◽  
Strong Inhibitor ◽  
Peripheral Blood Mononuclear ◽  
Inflammatory Cytokine Response ◽  
Complement Receptor 3 ◽  
Cholesterol Solubility

Atherosclerosis is an inflammatory condition and the underlying cause for cardiovascular disease. Cholesterol crystals (CC) are found to be abundant in atherosclerotic plaques and we have previously shown that CC initiate an inflammatory response via the complement system and inflammasome activation. Cyclic oligosaccharide 2-hydroxypropyl-β-cyclodextrin (BCD) is a compound that solubilizes lipophilic substances and is commonly used in pharmaceuticals or drug delivery. BCD is reported to increase cholesterol solubility and to promote the removal of cholesterol from foam cells. However, it remains unknown whether BCD has any effect on crystalline cholesterol. We here show that BCD attenuates the CC -induced inflammatory cytokine response as well as regulates a range of CC-related genes in human peripheral blood mononuclear cells. BCD binds to CC and prevents deposition of complement factors on CC in human plasma. Furthermore, BCD also decreases the formation of soluble terminal complement complex (TCC) and the expression of complement receptor 3 in response to CC stimulation in human whole blood. Induction of TCC by mono sodium urate crystals or zymosan was not affected by BCD. Of interest, after 1 hr of incubation, BCD is starting to dissolve the CC. These data demonstrate that BCD is a strong inhibitor of CC-induced inflammation, which might be explained by BCD-mediated attenuation of complement activation. These data suggest that BCD is a potential candidate for treatment of atherosclerosis.

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.

TNF-related apoptosis-inducing ligand (TRAIL) blocks osteoclastic differentiation induced by RANKL plus M-CSF

Blood ◽  
2004 ◽  
Vol 104 (7) ◽  
pp. 2044-2050 ◽  
Author(s):  
Giorgio Zauli ◽  
Erika Rimondi ◽  
Vanessa Nicolin ◽  
Elisabetta Melloni ◽  
Claudio Celeghini ◽  
...  
Keyword(s):  
P38 Mapk ◽  
Mononuclear Cells ◽  
Mapk Pathway ◽  
Human Peripheral Blood ◽  
Tartrate Resistant Acid Phosphatase ◽  
Cell Models ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Tnf Superfamily ◽  
Osteoclastic Differentiation

Abstract The role of the tumor necrosis factor (TNF) superfamily member receptor activator of nuclear factor kappa B ligand (RANKL) in promoting the differentiation of osteoclasts has been extensively characterized. In this study, we have investigated the effect of TNF-related apoptosis-inducing ligand (TRAIL), a member of the TNF superfamily of cytokines, in osteoclastogenesis, by using human peripheral blood mononuclear cells and the RAW264.7 murine monocytic cell line. Both cell models differentiate into osteoclast-like cells in presence of RANKL plus macrophage-colony-stimulating factor (M-CSF), as evaluated in terms of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells and bone resorption activity. Unexpectedly, when added in culture in combination with RANKL plus M-CSF, TRAIL inhibited osteoclastic differentiation in both cell models. To investigate the molecular mechanism underlining such inhibitory activity, we analyzed the effect of TRAIL on the mitogen-activated protein kinases (MAPKs) pathways, which play a key role in osteoclastogenesis. Treatment with RANKL plus M-CSF activated both the ERK1/2 and p38/MAPK pathways, which are essential for proliferation and differentiation of preosteoclasts, respectively. Of note, the addition of TRAIL to RANKL plus M-CSF did not affect ERK1/2 but it profoundly inhibited p38/MAPK phosphorylation. Thus, our data demonstrate that TRAIL blocks osteoclastic differentiation and suggest that inhibition of the p38/MAPK pathway by TRAIL likely plays an important role in this process. (Blood. 2004;104:2044-2050)

scholarly journals Development of Dual-Acting Pyrimidinediones as Novel and Highly Potent Topical Anti-HIV Microbicides

2011 ◽  
Vol 55 (11) ◽  
pp. 5243-5254 ◽  
Author(s):  
Karen Watson Buckheit ◽  
Lu Yang ◽  
Robert W. Buckheit
Keyword(s):  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Sexual Transmission ◽  
Therapeutic Index ◽  
Effective Vaccine ◽  
Peripheral Blood Mononuclear ◽  
Content Type ◽  
Subtype B ◽  
Sexual Transmission Of Hiv ◽  
Virus Strains

ABSTRACTIn the absence of an effective vaccine against the human immunodeficiency virus (HIV), topical microbicides to prevent the sexual transmission of HIV represent an important strategy to prevent the continued spread of infection. The recent trend in the development of new microbicide candidates includes the utilization of FDA-approved therapeutic drugs that target the early stages of the HIV life cycle, including entry inhibitors and reverse transcriptase inhibitors. We have investigated 12 pyrimidinedione compounds with potent HIV activities and their abilities to inhibit both virus entry and reverse transcription, in an effort to determine a lead microbicide for product development. The candidate compounds were evaluated for efficacy against subtype B, C, and E clinical virus strains in fresh human peripheral blood mononuclear cells and against CCR5-tropic virus strains in both monocyte-macrophages and dendritic cells. Microbicide-specific biological assays and toxicity evaluations were also performed in a variety of established and fresh human cells as well as againstLactobacillusstrains common to the vaginal environment. These evaluations resulted in the identification of congeners with cyclopropyl and cyclobutyl substituents at the N-1 of the pyrimidinedione as the most active molecules in the structure-activity relationship series. The pyrimidinediones represent excellent microbicide candidates in light of their significantly high efficacies against HIV-1 (subnanomolar concentration range), potencies (therapeutic index, >1 million), solubility profiles, and dual mechanism of antiviral action that includes two early steps of virus replication prior to the integration of the virus that are considered most important for microbicidal activity.

scholarly journals In Vitro and In Vivo Intracellular Killing Effects of Tigecycline against Clinical Nontyphoid Salmonella Isolates Using Ceftriaxone as a Comparator

2011 ◽  
Vol 55 (6) ◽  
pp. 2755-2759 ◽  
Author(s):  
Hung-Jen Tang ◽  
Wen-Chien Ko ◽  
Chi-Chung Chen ◽  
Po-Lin Chen ◽  
Han Siong Toh ◽  
...  
Keyword(s):  
Survival Rate ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Pathogen Resistance ◽  
Peripheral Blood Mononuclear ◽  
Content Type ◽  
Time Kill ◽  
Peritonitis Model

ABSTRACTSalmonellais an important, worldwide food-borne pathogen. Resistance to fluoroquinolones and cephalosporins has been increasingly reported, and new therapeutic agents are desperately needed. In this study, we evaluated thein vitroantimicrobial susceptibility of clinical nontyphoidalSalmonellaisolates to tigecycline. Antibacterial activity of tigecycline, ceftriaxone, and ciprofloxacin were investigated by time-kill studies and the murine peritonitis model. The MIC50/MIC90values of tigecycline, ceftriaxone, and ciprofloxacin against 76Salmonellaisolates were 0.25/0.5, 1/8, and 0.125/0.5 μg/ml, respectively. The intracellular inhibitory activity of tigecycline at 0.5 μg/ml (1× MIC) againstSalmonellaisolates in human peripheral blood mononuclear cells was sustained for 24 h. In a mouse peritonitis model, tigecycline reduced the extracellular and intracellular bacterial counts from 107CFU/ml and 105CFU/ml, respectively, to an undetectable level within 96 h. The results were similar to those obtained with ceftriaxone. The survival rate of mice exposed to tigecycline after being infected by an inoculum of 1 × 105CFU was 80%, and that of mice exposed to ceftriaxone was 100%. When the inoculum was increased to 1.3 × 106CFU, the survival rate of mice treated by tigecycline was 20%, and that of mice exposed to ceftriaxone was 0% (P= 0.2). When a ceftriaxone- and ciprofloxacin-resistant but tigecycline-susceptible isolate was tested, mice treated by tigecycline had a higher survival rate than those treated by ceftriaxone (15/20 [75%] versus 6/20 [30%];P= 0.011). Our results suggest that tigecycline is at least as effective as ceftriaxone for murineSalmonellainfections and warrants further clinical investigations to delineate its potential against humanSalmonellainfections.

Sign in / Sign up

Export Citation Format

Share Document