Modulation of lipopolysaccharide-induced proinflammatory cytokine production in vitro and in vivo by the herbal constituents apigenin (chamomile), ginsenoside Rb1 (ginseng) and parthenolide (feverfew)

2003 ◽  
Vol 41 (10) ◽  
pp. 1381-1390 ◽  
Author(s):  
Alexa T Smolinski ◽  
James J Pestka
2002 ◽  
Vol 70 (11) ◽  
pp. 6068-6074 ◽  
Author(s):  
Sofia Agelaki ◽  
Christos Tsatsanis ◽  
Achille Gravanis ◽  
Andrew N. Margioris

ABSTRACT Corticotropin-releasing hormone (CRH) exerts an anti-inflammatory effect indirectly, via cortisole production, and a proinflammatory effect directly on immune cells. The aim of the present work was to examine the effect of CRH on macrophage-derived cytokines both in vitro and in vivo. For the in vitro experiments we used two types of macrophages: (i) the RAW264.7 monocyte/macrophage cell line and (ii) thioglycolate-elicited peritoneal macrophages from BALB/c mice. We have found that CRH enhanced lipopolysaccharide (LPS)-induced tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), and IL-6 production. For the in vivo experiments we have used the LPS-induced endotoxin shock model in BALB/c mice, an established model for systemic inflammation in which macrophages are the major source of the proinflammatory cytokines responsible for the development of the shock. Administration of antalarmin, a synthetic CRH receptor 1 (CRHR1) antagonist, prior to LPS prolonged survival in a statistically significant manner. The effect was more evident at the early stages of endotoxin shock. CRHR1 blockade suppressed LPS-induced elevation of the macrophage-derived cytokines TNF-α, IL-1β, and IL-6, confirming the role of CRH signals in cytokine expression. In conclusion, our data suggest that CRH signals play an early and crucial role in augmenting LPS-induced proinflammatory cytokine production by macrophages. Our data suggest that the diffuse neuroendocrine system via CRH directly affects the immune system at the level of macrophage activation and cytokine production.


mBio ◽  
2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Andrew L. Garfoot ◽  
Qian Shen ◽  
Marcel Wüthrich ◽  
Bruce S. Klein ◽  
Chad A. Rappleye

ABSTRACTThe fungal pathogenHistoplasma capsulatumparasitizes host phagocytes. To avoid antimicrobial immune responses,Histoplasmayeasts must minimize their detection by host receptors while simultaneously interacting with the phagocyte. PathogenicHistoplasmayeast cells, but not avirulent mycelial cells, secrete the Eng1 protein, which is a member of the glycosylhydrolase 81 (GH81) family. We show thatHistoplasmaEng1 is a glucanase that hydrolyzes β-(1,3)-glycosyl linkages but is not required forHistoplasmagrowthin vitroor for cell separation. However,Histoplasmayeasts lacking Eng1 function have attenuated virulencein vivo, particularly during the cell-mediated immunity stage.Histoplasmayeasts deficient for Eng1 show increased exposure of cell wall β-glucans, which results in enhanced binding to the Dectin-1 β-glucan receptor. Consistent with this, Eng1-deficient yeasts trigger increased tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) cytokine production from macrophages and dendritic cells. While not responsible for large-scale cell wall structure and function, the secreted Eng1 reduces levels of exposed β-glucans at the yeast cell wall, thereby diminishing potential recognition by Dectin-1 and proinflammatory cytokine production by phagocytes. In α-glucan-producingHistoplasmastrains, Eng1 acts in concert with α-glucan to minimize β-glucan exposure: α-glucan provides a masking function by covering the β-glucan-rich cell wall, while Eng1 removes any remaining exposed β-glucans. Thus,HistoplasmaEng1 has evolved a specialized pathogenesis function to remove exposed β-glucans, thereby enhancing the ability of yeasts to escape detection by host phagocytes.IMPORTANCEThe success ofHistoplasma capsulatumas an intracellular pathogen results, in part, from an ability to minimize its detection by receptors on phagocytic cells of the immune system. In this study, we showed thatHistoplasmapathogenic yeast cells, but not avirulent mycelia, secrete a β-glucanase, Eng1, which reduces recognition of fungal cell wall β-glucans. We demonstrated that the Eng1 β-glucanase promotesHistoplasmavirulence by reducing levels of surface-exposed β-glucans on yeast cells, thereby enablingHistoplasmayeasts to escape detection by the host β-glucan receptor, Dectin-1. As a consequence, phagocyte recognition ofHistoplasmayeasts is reduced, leading to less proinflammatory cytokine production by phagocytes and less control ofHistoplasmainfectionin vivo. Thus,Histoplasmayeasts express two mechanisms to avoid phagocyte detection: masking of cell wall β-glucans by α-glucan and enzymatic removal of exposed β-glucans by the Eng1 β-glucanase.


2005 ◽  
Vol 288 (2) ◽  
pp. L317-L325 ◽  
Author(s):  
Branislava Janic ◽  
Todd M. Umstead ◽  
David S. Phelps ◽  
Joanna Floros

Ozone (O3), a major component of air pollution and a strong oxidizing agent, can lead to lung injury associated with edema, inflammation, and epithelial cell damage. The effects of O3on pulmonary immune cells have been studied in various in vivo and in vitro systems. We have shown previously that O3exposure of surfactant protein (SP)-A decreases its ability to modulate proinflammatory cytokine production by cells of monocyte/macrophage lineage (THP-1 cells). In this report, we exposed THP-1 cells and/or native SP-A obtained from bronchoalveolar lavage of patients with alveolar proteinosis to O3and studied cytokine production and NF-κB signaling. The results showed 1) exposure of THP-1 cells to O3significantly decreased their ability to express TNF-α in response to SP-A; TNF-α production, under these conditions, was still significantly higher than basal (unstimulated) levels in filtered air-exposed THP-1 cells; 2) exposure of both THP-1 cells and SP-A to O3did not result in any significant differences in TNF-α expression compared with basal levels; 3) O3exposure of SP-A resulted in a decreased ability of SP-A to activate the NF-κB pathway, as assessed by the lack of significant increase and decrease of the nuclear p65 subunit of NF-κB and cytoplasmic IκBα, respectively; and 4) O3exposure of THP-1 cells resulted in a decrease in SP-A-mediated THP-1 cell responsiveness, which did not seem to be mediated via the classic NF-κB pathway. These findings indicate that O3exposure may mediate its effect on macrophage function both directly and indirectly (via SP-A oxidation) and by involving different mechanisms.


2013 ◽  
Vol 81 (5) ◽  
pp. 1654-1662 ◽  
Author(s):  
Leonardo A. de Almeida ◽  
Gilson C. Macedo ◽  
Fábio A. V. Marinho ◽  
Marco T. R. Gomes ◽  
Patrícia P. Corsetti ◽  
...  

ABSTRACTBrucella abortusis recognized by several Toll-like receptor (TLR)-associated pathways triggering proinflammatory responses that affect both the nature and intensity of the immune response. Previously, we demonstrated thatB. abortus-mediated dendritic cell (DC) maturation and control of infection are dependent on the adaptor molecule MyD88. However, the involvement of all TLRs in response toB. abortusinfection is not completely understood. Therefore, we decided to evaluate the requirement for TLR6 in host resistance toB. abortus. Here, we demonstrated that TLR6 is an important component for triggering an innate immune response againstB. abortus. Anin vitroluciferase assay indicated that TLR6 cooperates with TLR2 to senseBrucellaand further activates NF-κB signaling. However,in vivoanalysis showed that TLR6, not TLR2, is required for the efficient control ofB. abortusinfection. Additionally,B. abortus-infected dendritic cells require TLR6 to induce tumor necrosis factor alpha (TNF-α) and interleukin-12 (IL-12). Furthermore, our findings demonstrated that the mitogen-activated protein kinase (MAPK) signaling pathway is impaired in TLR2, TLR6, and TLR2/6 knockout (KO) DCs when infected withB. abortus, which may account for the lower proinflammatory cytokine production observed in TLR6 KO mouse dendritic cells. In summary, the results presented here indicate that TLR6 is required to trigger innate immune responses againstB. abortusin vivoand is required for the full activation of DCs to induce robust proinflammatory cytokine production.


Cytokine ◽  
2021 ◽  
pp. 155510
Author(s):  
Milda Eimonte ◽  
Nerijus Eimantas ◽  
Laura Daniuseviciute ◽  
Henrikas Paulauskas ◽  
Astra Vitkauskiene ◽  
...  

Author(s):  
Yafei Rao ◽  
Xiaoyan Gai ◽  
Yanqing Le ◽  
Jing Xiong ◽  
Yujia Liu ◽  
...  

AimSmoker COPD patients with chest radiological signs of prior tuberculosis (TB) showed more severe lung damage, but the mechanisms remain unclear. Emerging evidence has implicated NK cells in the pathogenesis of both COPD and TB. The purpose of this study was to delineate the profile and cytokine production of NK-cell subpopulations and their immunometabolic changes after exposure to both cigarette smoke (CS) and Mycobacterium tuberculosis(MTB).MethodsWe profiled NK-cell subpopulations in terms of percentage and cytokine production by flow cytometry in smoker patients with pulmonary TB (PTB). In an in vitro coexposure model, we investigated proinflammatory cytokine production, glycolytic influx, and oxidative phosphorylation of NK cells under CS extract (CSE) and PPD costimulation.ResultsPeripheral blood NK cells in smoker patients with active PTB (CS+PTB group) showed altered proportion of subpopulations and excessive proinflammatory cytokine expressions. In vitro, CSE- and PPD-coexposed NK-92 cells displayed enhanced proinflammatory cytokine production, concurrent with decreased glycolytic influx and oxidative phosphorylation.ConclusionSmoker patients with active PTB showed enhanced proinflammatory cytokine expression within altered NK cell subpopulations. CSE and PPD coexposure induced heightened cytokine production concurrent with impaired cell metabolism in NK cells. These novel data suggest a potential role of NK cells in the pathogenesis of lung injury in subjects with coexposure to CS and TB.


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