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 ◽  
...  

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.

1998 ◽  
Vol 42 (8) ◽  
pp. 1911-1916 ◽  
Author(s):  
Anja Lührmann ◽  
Jürgen Thölke ◽  
Ingrid Behn ◽  
Jens Schumann ◽  
Gisa Tiegs ◽  
...  

ABSTRACT We show that the coumeromycin antibiotic novobiocin, a potent inhibitor of ADP ribosylation, prevents lipopolysaccharide (LPS)-induced tumor necrosis factor alpha (TNF-α), interleukin-1 (IL-1), IL-6, and IL-10 secretion in human peripheral blood mononuclear cells. It shares these cytokine-suppressing properties with other inhibitors of ADP ribosylation. We found that novobiocin prevents TNF-α production by inhibiting translation of the TNF-α mRNA. Elevated TNF-α levels in mice treated withd-galactosamine (GalN)-LPS or GalN-TNF were not reduced by novobiocin; however, the drug exhibited hepatoprotective properties. Novobiocin causes downregulation of the surface molecules on monocytes, among which CD14 was the most affected. The diminished expression of surface molecules was not observed on T and B lymphocytes. Similar to other inhibitors of ADP ribosylation, novobiocin prevents LPS-induced phosphate labelling of γ-actins.


2013 ◽  
Vol 91 (5) ◽  
pp. 353-361 ◽  
Author(s):  
Issaka Yougbaré ◽  
Gilles Boire ◽  
Michelle Roy ◽  
Claire Lugnier ◽  
Éric Rouseau

Systemic lupus erythematosus (SLE) is a polymorphic and multigenic autoimmune disease that evolves into progressive and chronic inflammation of multiple joints and organs. Phosphorylation and activation of p38 MAPK, along with the resulting overproduction of interleukin (IL)-1β, IL-6, and tumour necrosis factor (TNF)-α is a hallmark of inflammatory disorders. Here, we investigated the anti-inflammatory pathway modulated by NCS 613, a specific PDE4 inhibitor, on human peripheral blood mononuclear cells (PBMCs) from 5 healthy donors and 12 SLE patients. PDE4 subtypes, p38 MAPK, and IκBα protein levels were analyzed by Western blot, while NF-κB and PDE4B immunostaining was assessed in control and lipopolysaccharide (LPS) -pretreated PBMCs. Proinflammatory cytokines were quantified by ELISA, while IL-1β mRNA was resolved by RT–qPCR. NCS 613 treatment decreased PDE4B and upregulated PDE4C in human PBMCs from healthy donors and SLE patients. LPS stimulation increased p38 MAPK phosphorylation and NF-κB translocation to the nucleus, which was abolished by NCS 613 treatment. Concomitantly, NCS 613 restored IκBα detection levels in human PBMCs from both healthy donors and SLE patients. This compound also abolished LPS-induced inflammation in PBMCs by reducing IL-6, IL-8, and TNF-α cytokines. NCS 613 is a small molecule displaying anti-inflammatory properties that may provide an alternative or complementary strategy for SLE management.


1999 ◽  
Vol 67 (7) ◽  
pp. 3619-3624 ◽  
Author(s):  
Timothy L. Wyant ◽  
Michael K. Tanner ◽  
Marcelo B. Sztein

ABSTRACT The cytokine production patterns of human peripheral blood mononuclear cells (PBMC) in response to Salmonella typhiflagella (STF) were examined in culture supernatants of PBMC stimulated with STF. Consistent with previous findings in volunteers vaccinated with aroC aroD deletion mutants of S. typhi, PBMC from volunteers immunized with the licensed live Ty21a S. typhi vaccine secreted gamma interferon following exposure to STF. Stimulation with STF induced rapid de novo synthesis of tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β), followed by IL-6 and IL-10. Trypsin treatment of STF abrogated their effects, while polymyxin B had no effect. Intracellular cytokine measurements of STF-stimulated PBMC revealed the existence of monocyte subpopulations that produce only TNF-α, IL-1β or both cytokines. Moreover, STF markedly decreased the percentage of CD14+cells. These data demonstrate that STF are powerful monocyte activators which may have important implications for vaccine development and for understanding the pathogenesis of S. typhi infection.


1999 ◽  
Vol 6 (4) ◽  
pp. 594-598 ◽  
Author(s):  
Teresa Krakauer ◽  
Bradley G. Stiles

ABSTRACT Tumor necrosis factor alpha (TNF-α) is a critical cytokine that mediates the toxic effects of bacterial superantigens like staphylococcal enterotoxin B (SEB) and toxic shock syndrome toxin 1 (TSST-1). Pentoxifylline, an anti-inflammatory agent that inhibits endotoxemia and lipopolysaccharide (LPS)-induced release of TNF-α, was tested for its ability to inhibit SEB- and TSST-1-induced activation of human peripheral blood mononuclear cells (PBMCs) in vitro and toxin-mediated shock in mice. Stimulation of PBMCs by SEB or TSST-1 was effectively blocked by pentoxifylline (10 mM), as evidenced by the inhibition of TNF-α, interleukin 1β (IL-1β), gamma interferon (IFN-γ), and T-cell proliferation. The levels of TNF-α, IL-1α, and IFN-γ in serum after an SEB or TSST-1 injection were significantly lower in mice given pentoxifylline (5.5 mg/animal) versus control mice. Additionally, pentoxifylline diminished the lethal effects and temperature fluctuations elicited by SEB and TSST-1. Thus, in addition to treating endotoxemias, the cumulative in vitro and in vivo data suggest that pentoxifylline may also be useful in abrogating the ill effects of staphylococcal enterotoxins and TSST-1.


2008 ◽  
Vol 76 (5) ◽  
pp. 2164-2168 ◽  
Author(s):  
Thomas J. Scriba ◽  
Sophie Sierro ◽  
Eric L. Brown ◽  
Rodney E. Phillips ◽  
Andrew K. Sewell ◽  
...  

ABSTRACT The extracellular adhesion protein (Eap) secreted by the major human pathogen Staphylococcus aureus is known to have several effects on human immunity. We have recently added to knowledge of these roles by demonstrating that Eap enhances interactions between major histocompatibility complex molecules and human leukocytes. Several studies have indicated that Eap can induce cytokine production by human peripheral blood mononuclear cells (PBMCs). To date, there has been no rigorous attempt to identify the breadth of cytokines produced by Eap stimulation or to identify the cell subsets that respond. Here, we demonstrate that Eap induces the secretion of the proinflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) by CD14+ leukocytes (monocytes and macrophages) within direct ex vivo PBMC populations (note that granulocytes are also CD14+ but are largely depleted from PBMC preparations). Anti-intercellular adhesion molecule 1 (CD54) antibodies inhibited this induction and implicated a role for this known Eap binding protein in cellular activation. IL-6 and TNF-α secretion by murine cells exposed to Eap was also observed. The activation of CD14+ cells by Eap suggests that it could play a significant role in both septic shock and fever, two of the major pathological features of S. aureus infections.


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.


2012 ◽  
Vol 19 (11) ◽  
pp. 1889-1893 ◽  
Author(s):  
Kaarina Ranta ◽  
Kaisa Nieminen ◽  
Filip S. Ekholm ◽  
Moniká Poláková ◽  
Mattias U. Roslund ◽  
...  

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).


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