Fibrinogen and fibrin induce synthesis of proinflammatory cytokines from isolated peripheral blood mononuclear cells

2007 ◽  
Vol 97 (05) ◽  
pp. 822-829 ◽  
Author(s):  
Peter Kierulf ◽  
Per Sandset ◽  
Olav Klingenberg ◽  
Gunn Joø ◽  
Hans Godal ◽  
...  

SummaryFibrinogen in plasma includes three main fractions; high-molecular- weight (HMW) -fibrinogen, low-molecular-weight (LMW) -fibrinogen, and very-low-molecular-weight (LMW`) -fibrinogen. During acute-phase conditions, plasma fibrinogen levels and the HMW-/LMW-fibrinogen ratio increase rapidly due to increased synthesis of HMW-fibrinogen. The consequences of elevated plasma fibrinogen levels and local deposition of fibrin in inflammatory tissues observed during acute-phase conditions are not clear.We wanted to investigate proinflammatory effects of fibrinogen and fibrin on peripheral blood mononuclear cells (PBMC) as reflected by altered mRNA expression and synthesis of the proinflammatory cytokines IL-6,TNF- α and IL-1 β, and to explore the significance of altered HMW-/LMW-fibrinogen ratio. PBMC were isolated from whole blood using Lymphoprep® . HMW-fibrinogen was separated from unfractioned fibrinogen by ammonium sulphate precipitation. Cells were incubated with unfractioned fibrinogen, HMW-fibrinogen or fibrin. Cytokine levels in cell lysates were determined using ELISA assays. Real-time PCR was used for mRNA quantification. We found that fibrinogen significantly increased mRNA levels, and induced synthesis of the proinflammatory cytokines IL-6 and TNF- α in PBMC in a dose dependent manner. Median (25, 75 percentile) IL-6 and TNF- α concentrations were 12 (5, 40) pg/ ml and 16 (0,61) pg/ml,respectively.Median mRNA quantity was increased 12.3– (6.6, 48.6) and 1.7– (1.5, 6.5) fold for IL-6 and TNF- α compared to controls.The stimulatory effect of unfractioned fibrinogen was not significantly different from HMW-fibrinogen. Fibrinogen and fibrin were equally effective in promoting cytokine synthesis from PBMC.The results support that fibrin and fibrinogen may actively modulate the inflammatory process by inducing synthesis of proinflammatory cytokines from PBMC.

2018 ◽  
Author(s):  
Ana Vitlic ◽  
Sohaib Sadiq ◽  
Hafiz I. Ahmed ◽  
Elisa C. Ale ◽  
Ana G. Binetti ◽  
...  

ABSTRACTLactobacillus fermentumLf 2 produces large amounts of exopolysaccharides under optimized conditions (∼2 g/L, EPS) which have been shown to possess immunomodulatory activity. In this study, the crude EPS was fractionated to give a high molecular weight (HMw) homoglycan and a mixture of medium molecular weight heteroglycans. The HMw EPS was isolated and identified as a β-glucan.Peripheral blood mononuclear cells (PBMC) were pre-treated with purified polysaccharide to determine if the HMw β-glucan is responsible for the immunomodulatory activity. Cells were also stimulated with either lipopolysaccharide (LPS) or phytohemagglutinin (PHA) and their effects, both with and without β-glucan pre-treatment, compared.Exposure of the cells to β-glucan increased their metabolic activity and whilst a small but statistically significant drop in CD14 expression was observed at Day 1, the levels were significantly elevated at Day 2. High levels of CD14 expression were observed in cells initially exposed to the β-glucan and subsequently stimulated with either LPS or PHA. In contrast, reduced levels of TLR-2 expression were observed for cells initially exposed to the β-glucan and subsequently stimulated with LPS.TNF-α levels were elevated in β-glucan treated cells (Day1) with the levels dropping back once the β-glucan had been removed (Day 2). The stimulants LPS and PHA both induced significant rises in TNF-α levels, however, this induction was completely (LPS) or partially blocked (PHA) in β-glucan pre-treated cells.The results indicate a role for the bacterial β-glucan in modulating the immune response following exposure to agonists such as bacterial LPS.


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.


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