Candida tropicalis induces pro-inflammatory cytokine production, NF-κB and MAPKs pathways regulation, and dectin-1 activation

2018 ◽  
Vol 64 (12) ◽  
pp. 937-944 ◽  
Author(s):  
Zhimin Duan ◽  
Qing Chen ◽  
Rong Zeng ◽  
Leilei Du ◽  
Caixia Liu ◽  
...  

The prevalence of Candida infection induced by non-albicans Candida (NAC) species is increasing. However, as a common NAC species, C. tropicalis has received much less study in terms of host immunity than C. albicans has. In this study, we evaluated the pro-inflammatory cytokine responses evoked by C. tropicalis and determined whether dectin-1 and downstream NF-κB and mitogen-activated protein kinases (MAPKs) signaling pathways played roles in inflammation in human peripheral blood mononuclear cells (PBMCs) and THP-1 macrophage-like cells. Exposure of PBMCs and THP-1 macrophage-like cells to C. tropicalis led to the enhanced gene expression and secretion of TNF-α and IL-6 in a time- and dose-dependent manner. THP-1 macrophage-like cells being challenged by C. tropicalis resulted in the activation of the NF-κB, p38, and ERK1/2 MAPK signaling pathways. We also found that the expression of dectin-1 was increased with C. tropicalis treatment. These data reveal that dectin-1 may play a role in sensing the inflammation response induced by C. tropicalis and that NF-κB and MAPK are involved in the downstream signaling pathways in macrophages.

2003 ◽  
Vol 47 (12) ◽  
pp. 3704-3707 ◽  
Author(s):  
Jung-Hyun Choi ◽  
Min-Jin Song ◽  
Seung-Han Kim ◽  
Su-Mi Choi ◽  
Dong-Gun Lee ◽  
...  

ABSTRACT The effects of moxifloxacin, a new methoxyfluoroquinolone, on the production of proinflammatory cytokines from human peripheral blood mononuclear cells (PBMCs) were evaluated. Moxifloxacin inhibited the production of tumor necrosis factor alpha (TNF-α) and/or interleukin-6 (IL-6) by PBMCs stimulated with lipopolysaccharide (LPS), lipoteichoic acid (LTA), and heat-killed bacteria in a concentration-dependent manner without cytotoxic effects. The addition of moxifloxacin reduced the population of cells positive for CD-14 and TNF-α and for CD-14 and IL-6 among the LPS- or LTA-stimulated PBMCs. By Western blot analysis, moxifloxacin pretreatment reduced the degradation of IκBα in LPS-stimulated PBMCs. In conclusion, moxifloxacin could interfere with NF-κB activation by inhibiting the degradation of IκBα and reduce the levels of production of proinflammatory cytokines.


2009 ◽  
Vol 16 (12) ◽  
pp. 1804-1809 ◽  
Author(s):  
Giovanni Matera ◽  
Valentina Muto ◽  
Maria Vinci ◽  
Emilia Zicca ◽  
Shahla Abdollahi-Roodsaz ◽  
...  

ABSTRACT Veillonella parvula is an anaerobic gram-negative coccus that is part of the normal flora of the animal and human mouth and gastrointestinal and genitourinary tracts. Oral V. parvula is involved in the development of early periodontal disease as well as different types of serious infections. Present data on molecular mechanisms responsible for innate immune response against Veillonella are very scanty. The aim of this study was to investigate the Toll-like receptor (TLR) pathways responsible for V. parvula lipopolysaccharide (LPS) and to identify the intracellular pathways induced by this recognition. V. parvula LPS stimulated tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) release in human peripheral blood mononuclear cells (PBMC) in a dose-dependent manner. Pretreatment of cells with a TLR4 antagonist significantly reduced TNF-α and IL-6 production in PBMC stimulated with either Veillonella or Escherichia coli LPS. However, V. parvula LPS was 10- to 100-fold less active than E. coli LPS for cytokine induction. TNF-α, IL-1β, IL-6, and IL-10 were released in wild-type and TLR2−/−, but not TLR4−/−, mouse macrophage cultures. V. parvula LPS was able to activate the human PBMC p38 mitogen-activated protein kinase (MAPK). A specific p38 MAPK inhibitor strongly inhibited V. parvula LPS-induced TNF-α, IL-1β, IL-6, and IL-10. In conclusion, V. parvula LPS is able to induce cytokine production in both human and murine in vitro models, although it is less effective than Enterobacteriaceae LPS. V. parvula LPS-stimulated cytokine induction, as well as p38 MAPK activation, are TLR4-dependent features.


1981 ◽  
Vol 198 (2) ◽  
pp. 391-396 ◽  
Author(s):  
S M D'Souza ◽  
D J Englis ◽  
A Clark ◽  
R G Russell

1. Supernatant media from cultures of unstimulated human peripheral blood mononuclear cells contained one or more factors that increased by several hundred-fold the production of prostaglandin E by fibroblast-like cells derived from both inflamed and normal human gingival tissue. 2. This stimulation occurred in a dose-dependent manner and was completely inhibited by 14 microM-indomethacin. 3. Responsiveness to the factor declined as the age of the cell culture increased. 4. An increase in prostaglandin E production was first observed after a 2h exposure to the mononuclear cell factor(s) and could be prevented by cycloheximide. 5. Brief exposure (0.5 and 1.0 h) to mononuclear cell factor did not increase prostaglandin E production by the cells in a subsequent 72 h incubation in the absence of mononuclear cell factor. 6. Addition of arachidonate (10 microM and 15 microM) further enhanced stimulation of prostaglandin E production in response to mononuclear cell factor. 7. The stimulatory activity was resistant to digestion by trypsin, but was heat-labile, so that only 17% remained after treatment at 56 degrees C for 30 min.


2003 ◽  
Vol 228 (6) ◽  
pp. 749-758 ◽  
Author(s):  
Mirim Jin ◽  
Hyung Jin Jung ◽  
Jeong June Choi ◽  
Hyang Jeon ◽  
Jin Hwan Oh ◽  
...  

We isolated a water-soluble extract, PG101, from cultured mycelia of Lentinus lepideus. Treatment of human peripheral blood mononuclear cells (PBMCs) with PG101 increased levels of TNF-α, IL-1β, IL-10, and IL-12 by 100- to 1000-fold, whereas GM-CSF and IL-18 were activated by an order of magnitude. On the contrary, IFN-γ and IL-4 were not affected. The response to PG101 occurred in a dose- and time-dependent manner. From the human PBMCs treated with PG101, TNF-α was a first cytokine to be activated, detectable at 2 hr post-treatment followed by IL-1β at 6 hr post-treatment. IL-12 and IL-10 were the next to follow. GM-CSF and IL-18 both showed significant increases 24 hr after treatment. When PBMCs were sorted into various cell types, monocyte/macrophages, but not T and B cells, were the major target cell type responsive to PG101. Consistent with this result, the profile of cytokine expression upon PG101 treatment was comparable between PBMCs and a human promonocytic cell line (U937), whereas cell lines of T cell and myeloid origins did not respond to PG101. Data from a transient transfection assay involving specific reporter plasmids indicated that cellular transcription factor such as NF-κB, but not AP-1, was highly activated by PG101. Results from a gel retardation assay and the experiment involving a specific NF-κB inhibitor confirmed the involvement of NF-κB. Despite its significant biological effect on various cytokines, PG101 remained nontoxic in both rats and PBMCs even at a biological concentration approximately 20 times greater. PG101 demonstrates great potential as a therapeutic immune modulator.


Cytokine ◽  
2016 ◽  
Vol 88 ◽  
pp. 184-192 ◽  
Author(s):  
Hélio Galdino ◽  
Rodrigo Saar Gomes ◽  
Jessica Cristina dos Santos ◽  
Lívia Lara Pessoni ◽  
Anetícia Eduarda Maldaner ◽  
...  

2009 ◽  
Vol 77 (9) ◽  
pp. 3826-3837 ◽  
Author(s):  
Anna Martner ◽  
Susann Skovbjerg ◽  
James C. Paton ◽  
Agnes E. Wold

ABSTRACT Streptococcus pneumoniae is a major pathogen in humans. The pathogenicity of this organism is related to its many virulence factors, the most important of which is the thick pneumococcal capsule that minimizes phagocytosis. Another virulence-associated trait is the tendency of this bacterium to undergo autolysis in stationary phase through activation of the cell wall-bound amidase LytA, which breaks down peptidoglycan. The exact function of autolysis in pneumococcal pathogenesis is, however, unclear. Here, we show the selective and specific inefficiency of wild-type S. pneumoniae for inducing production of phagocyte-activating cytokines in human peripheral blood mononuclear cells (PBMC). Indeed, clinical pneumococcal strains induced production of 30-fold less tumor necrosis factor (TNF), 15-fold less gamma interferon (IFN-γ), and only negligible amounts of interleukin-12 (IL-12) compared with other closely related Streptococcus species, whereas the levels of induction of IL-6, IL-8, and IL-10 production were similar. If pneumococcal LytA was inactivated by mutation or by culture in a medium containing excess choline, the pneumococci induced production of significantly more TNF, IFN-γ, and IL-12 in PBMC, whereas the production of IL-6, IL-8, and IL-10 was unaffected. Further, adding autolyzed pneumococci to intact bacteria inhibited production of TNF, IFN-γ, and IL-12 in a dose-dependent manner but did not inhibit production of IL-6, IL-8, and IL-10 in response to the intact bacteria. Fragments from autolyzed bacteria inhibited phagocytosis of intact bacteria and reduced the in vitro elimination of pneumococci from human blood. Our results suggest that fragments generated by autolysis of bacteria with reduced viability interfere with phagocyte-mediated elimination of live pneumococci.


2018 ◽  
Vol 86 (4) ◽  
Author(s):  
Patricia F. Herkert ◽  
Jessica C. dos Santos ◽  
Ferry Hagen ◽  
Fatima Ribeiro-Dias ◽  
Flávio Queiroz-Telles ◽  
...  

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.


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