scholarly journals WNT ligands contribute to the immune response during septic shock and amplify endotoxemia-driven inflammation in mice

2017 ◽  
Vol 1 (16) ◽  
pp. 1274-1286 ◽  
Author(s):  
Marcela Gatica-Andrades ◽  
Dimitrios Vagenas ◽  
Jessica Kling ◽  
Tam T. K. Nguyen ◽  
Helen Benham ◽  
...  

Key Points Differential expression of WNT ligands in patients with septic shock and a mouse model of endotoxemia correlates with inflammatory cytokines. WNT ligands and WNT/β-catenin signaling positively regulate lipopolysaccharide-induced pro-inflammatory cytokines without impairing IL-10.

1970 ◽  
Vol 42 (2) ◽  
pp. 142-146
Author(s):  
EC Okocha ◽  
NC Ibeh ◽  
EO Ukaejiofor ◽  
JC Ebenebe ◽  
JC Aneke ◽  
...  

Background and Objective: In P. falciparum malaria (PFM) infestation there are marked changes in cytokine production as the body mounts an immune response to it. Hence we set out to study these changes.Methods: A total of 158 cases of PFM among children attending the paediatric unit of our hospital and 56 healthy controls were studied. Children with febrile illness were screened for malaria using 10% Giemsa stained blood smear. Patients with positive smears were recruited; co-infected patients – those infected by another organism in addition to plasmodium specie.- were excluded. Whole blood was collected, some into plain tubes for serum cytokine testing and some into EDTA bottles for complete blood count and parasite density (PD) determination. Controls with asymptomatic parasitaemia were excluded.Results: Using the World Health Organization criteria for defining severe malaria; we identified 15 cases of severe and 143 cases of uncomplicated PFM. Significantly elevated levels of interleukin-1 (IL-1), interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α) were seen in the uncomplicated and severe forms of PFM. It was observed that the elevated cytokine values correlated with PD (in uncomplicated PFM but not in the severe forms). The difference between PD/absolute monocyte count (AMC) ratio was not significant (p=0.13); while PD/platelet count (PC) and PC/ AMC ratios were significant (p=0.01, and 0.03 respectively) when compared between uncomplicated and severe disease.Conclusion: Our data seems to suggest that subjects with an adequate immune response to the parasite density, in terms of pro-inflammatory cytokine levels, presented with uncomplicated disease; while those who have an inadequate response presented with severe disease. The ratios of (PD/PC) and (PC/AMC), in the positive and negative directions respectively, may be predictors of increased disease severity. These observations may have implications for predicting disease outcome and PFM therapy.Key Words: plasmodium falciparum malaria, pro-inflammatory cytokines, Parasite density/Platelet count ratio, Platelet count/Absolute monocyte


Author(s):  
Bruna Lima Correa ◽  
Nadia El Harane ◽  
Ingrid Gomez ◽  
Hocine Rachid Hocine ◽  
José Vilar ◽  
...  

Abstract Aims The cardioprotective effects of human induced pluripotent stem cell-derived cardiovascular progenitor cells (CPC) are largely mediated by the paracrine release of extracellular vesicles (EV). We aimed to assess the immunological behaviour of EV-CPC, which is a prerequisite for their clinical translation. Methods and results Flow cytometry demonstrated that EV-CPC expressed very low levels of immune relevant molecules including HLA Class I, CD80, CD274 (PD-L1), and CD275 (ICOS-L); and moderate levels of ligands of the natural killer (NK) cell activating receptor, NKG2D. In mixed lymphocyte reactions, EV-CPC neither induced nor modulated adaptive allogeneic T cell immune responses. They also failed to induce NK cell degranulation, even at high concentrations. These in vitro effects were confirmed in vivo as repeated injections of EV-CPC did not stimulate production of immunoglobulins or affect the interferon (IFN)-γ responses from primed splenocytes. In a mouse model of chronic heart failure, intra-myocardial injections of EV-CPC, 3 weeks after myocardial infarction, decreased both the number of cardiac pro-inflammatory Ly6Chigh monocytes and circulating levels of pro-inflammatory cytokines (IL-1α, TNF-α, and IFN-γ). In a model of acute infarction, direct cardiac injection of EV-CPC 2 days after infarction reduced pro-inflammatory macrophages, Ly6Chigh monocytes, and neutrophils in heart tissue as compared to controls. EV-CPC also reduced levels of pro-inflammatory cytokines IL-1α, IL-2, and IL-6, and increased levels of the anti-inflammatory cytokine IL-10. These effects on human macrophages and monocytes were reproduced in vitro; EV-CPC reduced the number of pro-inflammatory monocytes and M1 macrophages, while increasing the number of anti-inflammatory M2 macrophages. Conclusions EV-CPC do not trigger an immune response either in in vitro human allogeneic models or in immunocompetent animal models. The capacity for orienting the response of monocyte/macrophages towards resolution of inflammation strengthens the clinical attractiveness of EV-CPC as an acellular therapy for cardiac repair.


2020 ◽  
Vol 51 (1) ◽  
Author(s):  
Lianci Peng ◽  
Maaike R. Scheenstra ◽  
Roel M. van Harten ◽  
Henk P. Haagsman ◽  
Edwin J. A. Veldhuizen

Abstract Cathelicidins (CATHs) play an important role in the innate immune response against microbial infections. Among the four chicken cathelicidins, CATH-B1 is studied the least. In this study, the effect of CATH-B1 on the macrophage response towards avian pathogenic E. coli (APEC) and bacterial ligands was investigated. Our results show that APEC induced CATH-B1 gene expression in both a chicken macrophage cell line (HD11 cells) and primary macrophages, while expression of the other three CATHs was virtually unaffected. While the antimicrobial activity of CATH-B1 is very low under cell culture conditions, it enhanced bacterial phagocytosis by macrophages. Interestingly, CATH-B1 downregulated APEC-induced gene expression of pro-inflammatory cytokines (IFN-β, IL-1β, IL-6 and IL-8) in primary macrophages. In addition, CATH-B1 pre-incubated macrophages showed a significantly higher gene expression of IL-10 after APEC challenge, indicating an overall anti-inflammatory profile for CATH-B1. Using isothermal titration calorimetry (ITC), CATH-B1 was shown to bind LPS. This suggests that CATH-B1 reduces toll like receptor (TLR) 4 dependent activation by APEC which may partly explain the decreased production of pro-inflammatory cytokines by macrophages. On the contrary, direct binding of CATH-B1 to ODN-2006 enhanced the TLR21 dependent activation of macrophages as measured by nitric oxide production. In conclusion, our results show for the first time that CATH-B1 has several immunomodulatory activities and thereby could be an important factor in the chicken immune response.


2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S170-S170
Author(s):  
X Wu ◽  
X Liu ◽  
N Lan ◽  
X Zheng ◽  
Y Chen ◽  
...  

Abstract Background Patients with inflammatory bowel disease (IBD) are at a higher risk of developing colitis-associated colorectal cancer. The aim of the present study was to investigate the role of CD73 in IBD-associated tumourigenesis. Methods A mouse model of colitis-associated tumourigenesis (CAT) induced by azoxymethane and dextran sulphate sodium (AOM/DSS) was successfully constructed. Model mice were injected with CD73 inhibitor or adenosine receptor agonist. Colon length, body weight loss and tumour formation were assessed macroscopically. Measurement of inflammatory cytokines and RNA sequencing on colon tissues were performed. Results Inhibition of CD73 by adenosine 5′-(α,β-methylene) diphosphate (APCP) suppressed the severity of CAT with attenuated weight loss, longer colons, lower tumour number and smaller tumour size when compared with the model group. On the other hand, activation of adenosine receptors using 1-(6-amino-9H-purin-9-yl)-1-deoxy-N-ethyl-β-d-ribofuranuronamide (NECA) exacerbated CAT. Histological assessment indicated that inhibition of CD73 reduced while activation of adenosine receptors exacerbated the histological damage of the colon compared with the model group. Increased expression of pro-inflammatory cytokines (tumour necrosis factor-α and interleukin-6) in colonic tissue was detected in the NECA group. According to the results of RNA sequencing, potential oncogenes such as ALOX15, Bcl2l15 and Nat8l were found to be downregulated in the APCP group and upregulated in the NECA group compared with the model group. Conclusion Therefore, inhibition of CD73 attenuated IBD-associated tumourigenesis, while activation of adenosine receptors exacerbated tumourigenesis in a C57BL/6J mouse model. This effect may be associated with the expression of pro-inflammatory cytokines and the regulation of ALOX15, Bcl2l15 and Nat8l.


2021 ◽  
Author(s):  
Brenda Ramírez-Aguero ◽  
Javier Serrato-Salas ◽  
José Luis Montiel-Hernández ◽  
Judith González-Christen

AbstractSeveral pathogenic mechanisms have been linked to the severity of dengue virus infection, like viral cytotoxicity, underlying host genetics and comorbidities such as diabetes and dyslipidemia. It has been observed that patients with severe manifestations develop an uncontrolled immune response, with an increase in pro-inflammatory cytokines such as TNF, IL-1β, IL-8, IL-6 and chemokines that damage the human microvascular endothelium, and also in anti-inflammatory cytokines IL-4, IL-10 and TGF-β1. The role of TGF-β1 on dengue is not clear; few studies have been published, and most of them from patient sera data, with both protective and pathological roles have described. The aim of this study was to evaluate the ability of TGF-β1 to regulate the secretion of IL-1β in macrophages infected by DENV using THP-1 cells treated with recombinant TGF-β1 before or after DENV infection. By RT-PCR we did not observe a difference in IL-1β expression between infected cells pretreated with TGF-β1 and those that were not. However, secretion of IL-1β was reduced only in cells stimulated with TGF-β1 before infection, and not in those treated 2 hours post-infection. TGF-β1 receptor blockage with SB505124 inhibitor, prior to the addition of TGF-β1 and infection, abrogated the inhibitory effect of TGF-β1. Our results suggest that DENV could regulate the function of TGF-β1 on macrophages. This negative regulation of the TGF-β1 pathway could be used by DENV to evade the immune response and could contribute to the immunopathology.


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