IL-33 Enhances the Lipopolysaccharide-Induced Secretion of Inflammatory Cytokines and Ameliorates Lipopolysaccharide Desensitization in Macrophages

2022 ◽  
Vol 12 (2) ◽  
pp. 346-351
Author(s):  
Dong-Yang Guo ◽  
Zhou-Xin Yang ◽  
Guo-Long Cai ◽  
Ling-Zhi Shen ◽  
Ying-Xing Yue ◽  
...  

Background: Lipopolysaccharide (LPS) desensitization, which is characterized by hyporesponsiveness and a form of immunosuppression, is important in the negative regulation of responses to LPS and inflammatory disease such as sepsis. However, effect of IL-33 in the desensitization to LPS remains unclear. Methods: We used RNA-sequencing technology to analyze changes in mRNA in bone-marrow-derived macrophages (BMDMs) stimulated with LPS. Changes in expression and secretion of inflammatory cytokines were detected by qPCR and ELISA, respectively. Mechanisms were further studied through p65 phosphorylation detection. Results: IL-33 expression was significantly increased in LPS-treated macrophages, indicating its involvement in LPS-induced inflammation. Exogenous IL-33 increased the inflammatory response and ameliorated LPS desensitization by increasing the secretion of proinflammatory cytokines. It also activated p65 phosphorylation in resistant cells. Conclusion: IL-33 can enhance the inflammatory response induced by LPS and ameliorate LPS desensitization possibly by activating the NF-κB pathway in mouse macrophages.

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Yong Wang ◽  
Wentao Qi ◽  
Ge Song ◽  
Shaojie Pang ◽  
Zhenzhen Peng ◽  
...  

High-fructose diet induced changes in gut microbiota structure and function, which have been linked to inflammatory response. However, the effect of small or appropriate doses of fructose on gut microbiota and inflammatory cytokines is not fully understood. Hence, the abundance changes of gut microbiota in fructose-treated Sprague-Dawley rats were analyzed by 16S rRNA sequencing. The effects of fructose diet on metabolic disorders were evaluated by blood biochemical parameter test, histological analysis, short-chain fatty acid (SCFA) analysis, ELISA analysis, and Western blot. Rats were intragastrically administered with pure fructose at the dose of 0 (Con), 2.6 (Fru-L), 5.3 (Fru-M), and 10.5 g/kg/day (Fru-H) for 20 weeks. The results showed that there were 36.5% increase of uric acid level in the Fru-H group when compared with the Con group. The serum proinflammatory cytokines (IL-6, TNF-α, and MIP-2) were significantly increased ( P < 0.05 ), and the anti-inflammatory cytokine IL-10 was significantly decreased ( P < 0.05 ) with fructose treatment. A higher fructose intake induced lipid accumulation in the liver and inflammatory cell infiltration in the pancreas and colon and increased the abundances of Lachnospira, Parasutterella, Marvinbryantia, and Blantia in colonic contents. Fructose intake increased the expressions of lipid accumulation proteins including perilipin-1, ADRP, and Tip-47 in the colon. Moreover, the higher level intake of fructose impaired intestinal barrier function due to the decrease of the expression of tight junction proteins (ZO-1 and occludin). In summary, there were no negative effects on body weight, fasting blood glucose, gut microbiota, and SCFAs in colonic contents of rats when fructose intake is in small or appropriate doses. High intake of fructose can increase uric acid, proinflammatory cytokines, intestinal permeability, and lipid accumulation in the liver and induce inflammatory response in the pancreas and colon.


2021 ◽  
Author(s):  
Shahanshah Khan ◽  
Mahnoush S. Shafiei ◽  
Christopher Longoria ◽  
John Schoggins ◽  
Rashmin C. Savani ◽  
...  

Pathogenesis of COVID-19 is associated with a hyperinflammatory response; however, the precise mechanism of SARS-CoV-2-induced inflammation is poorly understood. Here we investigated direct inflammatory functions of major structural proteins of SARS-CoV-2. We observed that spike (S) protein potently induces inflammatory cytokines and chemokines including IL-6, IL-1b, TNFa, CXCL1, CXCL2, and CCL2, but not IFNs in human and mouse macrophages. No such inflammatory response was observed in response to membrane (M), envelope (E), and neucleocapsid (N) proteins. When stimulated with extracellular S protein, human lung epithelial cells A549 also produce inflammatory cytokines and chemokines. Interestingly, epithelial cells expressing S protein intracellularly are non-inflammatory, but elicit an inflammatory response in macrophages when co-cultured. Biochemical studies revealed that S protein triggers inflammation via activation of the NF-kB pathway in a MyD88-dependent manner. Further, such an activation of the NF-kB pathway is abrogated in Tlr2-deficient macrophages. Consistently, administration of S protein induces IL-6, TNF-a, and IL-1b in wild-type, but not Tlr2-deficient mice. Together these data reveal a mechanism for the cytokine storm during SARS-CoV-2 infection and suggest that TLR2 could be a potential therapeutic target for COVID-19.


Author(s):  
Xudong Pu ◽  
Xin Li ◽  
Lili Cao ◽  
Kaiming Yue ◽  
Panpan Zhao ◽  
...  

Giardia duodenalis, also known as Giardia lamblia or Giardia intestinalis, is an important opportunistic, pathogenic, zoonotic, protozoan parasite that infects the small intestines of humans and animals, causing giardiasis. Several studies have demonstrated that innate immunity-associated Toll-like receptors (TLRs) are critical for the elimination of G. duodenalis; however, whether TLR9 has a role in innate immune responses against Giardia infection remains unknown. In the present study, various methods, including reverse transcriptase–quantitative polymerase chain reaction, Western blot, enzyme-linked immunosorbent assay, immunofluorescence, inhibitor assays, and small-interfering RNA interference, were utilized to probe the role of TLR9 in mouse macrophage-mediated defenses against G. lamblia virus (GLV)–free or GLV-containing Giardia trophozoites. The results revealed that in G. duodenalis–stimulated mouse macrophages, the secretion of proinflammatory cytokines, including interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), and IL-12 p40, was enhanced, concomitant with the significant activation of TLR9, whereas silencing TLR9 attenuated the host inflammatory response. Notably, the presence of GLV exacerbated the secretion of host proinflammatory cytokines. Moreover, G. duodenalis stimulation activated multiple signaling pathways, including the nuclear factor κB p65 (NF-κB p65), p38, ERK, and AKT pathways, the latter three in a TLR9-dependent manner. Additionally, inhibiting the p38 or ERK pathway downregulated the G. duodenalis–induced inflammatory response, whereas AKT inhibition aggravated this process. Taken together, these results indicated that G. duodenalis may induce the secretion of proinflammatory cytokines by activating the p38 and ERK signaling pathways in a TLR9-dependent manner in mouse macrophages. Our in vitro findings on the mechanism underlying the TLR9-mediated host inflammatory response may help establish the foundation for an in-depth investigation of the role of TLR9 in the pathogenicity of G. duodenalis.


2005 ◽  
Vol 288 (4) ◽  
pp. L633-L640 ◽  
Author(s):  
Alix Ashare ◽  
Linda S. Powers ◽  
Noah S. Butler ◽  
Kevin C. Doerschug ◽  
Martha M. Monick ◽  
...  

Using a murine model of sepsis, we found that the balance of tissue pro- to anti-inflammatory cytokines directly correlated with severity of infection and mortality. Sepsis was induced in C57BL/6 mice by cecal ligation and puncture (CLP). Liver tissue was analyzed for levels of IL-1β, IL-1 receptor antagonist (IL-1ra), tumor necrosis factor (TNF)-α, and soluble TNF receptor 1 by ELISA. Bacterial DNA was measured using quantitative real-time PCR. After CLP, early predominance of proinflammatory cytokines (6 h) transitioned to anti-inflammatory predominance at 24 h. The elevated anti-inflammatory cytokines were mirrored by increased tissue bacterial levels. The degree of anti-inflammatory response compared with proinflammatory response correlated with the bacterial concentration. To modulate the timing of the anti-inflammatory response, mice were treated with IL-1ra before CLP. This resulted in decreased proinflammatory cytokines, earlier bacterial load, and increased mortality. These studies show that the initial tissue proinflammatory response to sepsis is followed by an anti-inflammatory response. The anti-inflammatory phase is associated with increased bacterial load and mortality. These data suggest that it is the timing and magnitude of the anti-inflammatory response that predicts severity of infection in a murine model of sepsis.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Panpan Zhao ◽  
Lili Cao ◽  
Xiaocen Wang ◽  
Jianhua Li ◽  
Jingquan Dong ◽  
...  

Abstract Background Giardia duodenalis is an extracellular protozoan parasite that causes giardiasis in mammals. The presentation of giardiasis ranges from asymptomatic to severe diarrhea, and the World Health Organization lists it in the Neglected Diseases Initiative. Extracellular vesicles (EVs) are a key mediator of intracellular communication. Although previous studies have shown that G. intestinalis can regulate a host’s innate immune response, the role of G. intestinalis EVs (GEVs) in triggering a G. intestinalis-induced innate immune response remains to be further explored. Methods In this study, GEVs, G. intestinalis and GEVs + G. intestinalis were inoculated into macrophages, respectively. The transcription and secretion levels of proinflammatory cytokines, including interleukin (IL)-1β, IL-6 and tumor necrosis factor alpha (TNF-α), were measured using real-time quantitative PCR (qPCR) and enzyme-linked immunosorbent assays (ELISAs). The phosphorylation levels of the MAPK, AKT and NF-κB signaling pathways in GEV-stimulated mouse macrophages were examined using western blotting and immunofluorescence methods. The roles of activated pathways in the GEV-triggered inflammatory response were determined using inhibition assays, western blotting and ELISAs. Results The results showed that pretreatment with GEVs enhanced with G. intestinalis (GEVs + G. intestinalis) induced IL-1β, IL-6 and TNF-α transcription and secretion from mouse macrophages compared to stimulation with either GEVs or G. intestinalis alone. Inoculation of mouse macrophages with GEVs upregulated the phosphorylation levels of the p38 MAPK, p44/42 MAPK (Erk1/2), AKT and NF-κB signaling pathways and led to the nuclear translocation of NF-κB p65. Blocking the activated p38, Erk and NF-κB signaling pathways significantly downregulated the secretion of proinflammatory cytokines, and blocking the activated AKT signaling pathway demonstrated reverse effects. Conclusions The results of this study reveal that GEVs can enhance G. intestinalis-induced inflammatory response levels in mouse macrophages through activation of the p38, ERK and NF-κB signaling pathways. The role of GEVs in regulating host cell immune responses may provide insights into exploring the underlying mechanisms in G. intestinalis–host interactions. Graphical abstract


2021 ◽  
Author(s):  
Yuping Song ◽  
Qicong Pan ◽  
Jing Xiao ◽  
Wenjie Li ◽  
Hui Ma ◽  
...  

Siglecs are sialic acid-binding immunoglobulin-like lectins that play an important role in tissue homeostasis, immune response, and pathogen infection. Bacterial sialidases act on natural ligands of Siglecs, interfering with the Siglec-mediated immune response. Glaesserella parasuis is a porcine bacterial pathogen that secretes sialidase. However, little is known about the sialidase of G. parasuis and its impact on immune regulation. Here, we used wild-type G. parasuis, a sialidase-deficient mutant, and complimentary strains to investigate the role of sialidase in porcine alveolar macrophage infection. Sialidase induced the release of proinflammatory cytokines, such as interleukin (IL)-1α, IL-6, and tumor necrosis factor alpha, from porcine alveolar macrophages. Moreover, sialidase desialylated the surface of porcine alveolar macrophages and altered the expression of Siglecs (the expression of Siglec-5 was reduced). Furthermore, sialidase led to a reduction in endogenous SH2 domain-containing protein tyrosine phosphatase (SHP-2) recruitment to Siglec-5 and simultaneously activated the inflammatory response via the mitogen-activated protein kinase and nuclear factor kappa light chain enhancer of activated B cell signaling pathways. This desialylation occurred before the release of proinflammatory cytokines, suggesting that the sialidase-induced inflammatory response was followed by reduced recruitment of SHP-2 to Siglec-5. Thus, this study is the first to demonstrate the role of sialidase in the inflammatory response of G. parasuis. This role resulted from the abrogation of negative regulation of Siglec-5 on proinflammatory cytokine release. This study helps to understand the molecular mechanism underlying the inflammatory response induced by sialidase secreted by G. parasuis and the acute inflammation caused by G. parasuis.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4957-4957
Author(s):  
Ullas Mony ◽  
Theertha M ◽  
Neeraj Sidharthan ◽  
Veeraraghavan Vishnu Priya ◽  
Praveen K Varma

Abstract INTRODUCTION Sepsis caused by a dysregulated host response to infection, is a serious healthcare problem that results in very high mortality every year-round the globe. When left untreated, sepsis can potentially turn fulminant, making early diagnosis and intervention an essential component of the therapeutic strategy. Proinflammatory cytokines are necessary for initiating an effective inflammatory response against infection, whereas their excess production has been associated with tissue injury in multiple organ systems leading to increased mortality. In contrast, anti-inflammatory cytokines seem to be a prerequisite for controlling and down regulating the initial inflammatory response. But a sustained release of these biomolecules leads to a turn-down of immune activation within the host organism. In the clinical conundrums associated with sepsis, it was often observed that pathogen-responsive cells were exposed to a complex cytokine milieu. The excess production of proinflammatory cytokines is essential for the survival, replication and activation of phagocytic and cytotoxic immune cells. In conjunction with this proinflammatory activity, anti-inflammatory cytokines are also released which are involved in the occurrence of cellular anergy and impaired response to aetiologic agents, causing a compensatory anti-inflammatory response syndrome (CARS). Current practice in cardiac surgery is to review laboratory test results (CRP, PCT, blood culture) and clinical criteria (SOFA and STS) 48 h after surgery to diagnose sepsis. CRP and PCT lack sensitivity and specificity, whereas blood culture requires a long turnaround time and lacks sensitivity. Sepsis being an interplay between pro and anti-inflammatory response, the relative expression of immune biomarkers may provide a useful criterion for early diagnosis of sepsis. Thus, we aimed at investigating the variations in circulating levels of prominent cytokines and their potential use as a diagnostic marker of adult sepsis post cardiac surgery. MATERIALS AND METHODS In this double-blinded cohort study, blood samples of adult patients undergoing cardiac surgery were collected before surgery (D -1), and on the post-operative day 1 (D +1) after the approval from the appropriate Institutional Ethics Committee. Patients who were deemed risky by EuroSCORE II risk stratification were included and immuno-compromised as well as patients with active infection before surgery were excluded. Plasma levels of IL-1β, IL-5, IL-6, IL-10, IL-17A and TNFα were determined using cytometric bead assay by flow cytometry and the results were analyzed using FCAP Array™ software. The data sets were analyzed (GraphPad Prism 5.02) and a p value of &lt; 0.05 was considered statistically significant. RESULTS The study was conducted with 34 patients (n=34) and un-blinded after retrieval of data. The cohort has 8 patients diagnosed with sepsis and 26 without sepsis based on STS criteria. Demographic details for both groups are summarized in Table 1. Cytokine and other biomarker expression levels before (D-1) and after (D+1) Surgery is summarized in Table 2. At D +1, IL-1β, TNF-α, IL-17A and IL-10 showed significantly higher concentration in sepsis group compared to non-sepsis group (Fig 1B). CRP, PCT, WBC and differential blood count were not showing any discriminatory potential between sepsis and non-sepsis patients at D +1. The ROC curves of the above four cytokine expression levels at D+1 was analyzed between sepsis and non-sepsis groups. A plasma IL-1β level of 0.25 pg/ml had a sensitivity of 87.5 % and a specificity of 53.8 % and a plasma IL-17A level of 1.78 pg/ml had a sensitivity of 75 % and specificity of 46.2 %. In addition, IL-10 level of 8.99 pg/ml in plasma showed a diagnostic sensitivity of 87.5 % and a specificity of 53.8% (Fig 1C). Based on the current observation we proposed a model of inflammatory cytokine dynamics involving IL-1β, IL-17A and IL-10 suggesting their role, which may lead to the development of sepsis (Fig 1D). CONCLUSION We identified a significant up regulation of circulating inflammatory cytokines at 24 h in patients who developed sepsis after cardiac surgery, earlier than any noticeable changes in conventional sepsis biomarkers. These results suggest the possibility of inflammatory cytokines as a diagnostic marker and may be a potential therapeutic target as well. The study needs to be validated further on a larger cohort of patients. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Shahanshah Khan ◽  
Mahnoush Shafiei ◽  
Christopher Longoria ◽  
John W Schoggins ◽  
Rashmin Savani ◽  
...  

The pathogenesis of COVID-19 is associated with a hyperinflammatory response; however, the precise mechanism of SARS-CoV-2-induced inflammation is poorly understood. Here we investigated direct inflammatory functions of major structural proteins of SARS-CoV-2. We observed that spike (S) protein potently induced inflammatory cytokines and chemokines including IL-6, IL-1b, TNFa, CXCL1, CXCL2, and CCL2, but not IFNs in human and mouse macrophages. No such inflammatory response was observed in response to membrane (M), envelope (E), and nucleocapsid (N) proteins. When stimulated with extracellular S protein, human and mouse lung epithelial cells also produced inflammatory cytokines and chemokines. Interestingly, epithelial cells expressing S protein intracellularly were non-inflammatory, but elicited an inflammatory response in macrophages when co-cultured. Biochemical studies revealed that S protein triggers inflammation via activation of the NF-kB pathway in a MyD88-dependent manner. Further, such an activation of the NF-kB pathway was abrogated in Tlr2-deficient macrophages. Consistently, administration of S protein induced IL-6, TNF-a, and IL-1b in wild-type, but not Tlr2-deficient mice. Notably, upon recognition of S protein, TLR2 dimerizes with TLR1 or TLR6 to activate the NF-kB pathway. Together these data reveal a mechanism for the cytokine storm during SARS-CoV-2 infection and suggest that TLR2 could be a potential therapeutic target for COVID-19.


2016 ◽  
pp. 73-76
Author(s):  
B.M. Ventskivskiy ◽  
◽  
I.V. Poladych ◽  
S.O. Avramenko ◽  
◽  
...  

In recent years there has been an increase in the frequency of multiple pregnancies and the associated perinatal losses. It is a result of multiple pregnancy in ART refers to a high-risk gestation, at which premature births occur in 2 times more often than in singleton pregnancies. The objective: to determine the role of pro-inflammatory cytokines in the pathogenesis of premature labor in multiple pregnancy, as a result of assisted reproductive technology. Patients and methods. to determine the pro-inflammatory cytokines that all pregnant with bagtopliddyam held immunosorbent assay, defined concentrations of interleukin (IL) in serum and cervical mucus. Results. The analysis of the levels of pro-inflammatory cytokines (IL-1, IL-8) in the test environment, found high concentrations in the surveyed women with multiple pregnancy, due to the use of ART, compared with spontaneous multiple and singleton pregnancy. Increased concentration of proinflammatory cytokines in patients with multiple pregnancy by ART is associated with their synthesis at the system level, it stimulated foci of inflammation in the female genitals and extragenital localization. This correlates with the clinical data and statistical analysis, patients with multiple pregnancy as a result of ART had weighed infectious-inflammatory history. Conclusion. The study showed that elevated levels of proinflammatory cytokines in the systemic and local level in patients with multiple pregnancy due to ART, typical for women with miscarriage, because of the physiological course of pregnancy characterized by the predominance of anti-inflammatory cytokines that prevent rejection of the fetus as a foreign factor. Based on the data obtained proved the role of systemic inflammatory factors in the genesis of preterm labor in women with a multiple pregnancy, as a result of assisted reproductive technology. Key words: multiple pregnancy, assisted reproductive technology, premature birth, interleukine-1, interleukine-8.


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