Neutrophil extracellular traps (NETs) and the role of platelets in infection

2014 ◽  
Vol 112 (10) ◽  
pp. 659-665 ◽  
Author(s):  
Robert Andrews ◽  
Jane Arthur ◽  
Elizabeth Gardiner
Keyword(s):  
Immune Responses ◽  
Platelet Function ◽  
Inflammatory Responses ◽  
Neutrophil Extracellular Traps ◽  
Nuclear Material ◽  
Extracellular Traps ◽  
Tumour Metastasis ◽  
Activated Neutrophils ◽  
Infection And Inflammation

SummaryIn addition to playing a central role in normal haemostasis, platelets make important contributions to host inflammatory and immune responses to injury or infection. Under pathophysiological conditions where platelet function is not tightly controlled, platelets also play critical roles in pathogenic processes underlying cardiovascular disease, uncontrolled inflammation, coagulopathy and in tumour metastasis. Neutrophil extracellular traps (NETs) are webs of histone-modified nuclear material extruded from activated neutrophils during inflammatory responses and these degranulation events can be directly triggered by platelet/neutrophil engagement. Emerging research describes how NETs influence platelet function, particularly in the setting of infection and inflammation. Especially intriguing is the potential for platelet-driven coagulation to be modulated by NETs in plasma and interstitial spaces. These findings also reveal new perspectives related to improved therapy for venous thrombosis.

scholarly journals SARS-CoV-2–triggered neutrophil extracellular traps mediate COVID-19 pathology

2020 ◽  
Vol 217 (12) ◽  
Author(s):  
Flavio Protasio Veras ◽  
Marjorie Cornejo Pontelli ◽  
Camila Meirelles Silva ◽  
Juliana E. Toller-Kawahisa ◽  
Mikhael de Lima ◽  
...  
Keyword(s):  
Inflammatory Diseases ◽  
Tracheal Aspirate ◽  
Neutrophil Extracellular Traps ◽  
Angiotensin Converting Enzyme 2 ◽  
Extracellular Traps ◽  
Lung Epithelial ◽  
Activated Neutrophils ◽  
Epithelial Cell Death

Severe COVID-19 patients develop acute respiratory distress syndrome that may progress to cytokine storm syndrome, organ dysfunction, and death. Considering that neutrophil extracellular traps (NETs) have been described as important mediators of tissue damage in inflammatory diseases, we investigated whether NETs would be involved in COVID-19 pathophysiology. A cohort of 32 hospitalized patients with a confirmed diagnosis of COVID-19 and healthy controls were enrolled. The concentration of NETs was augmented in plasma, tracheal aspirate, and lung autopsies tissues from COVID-19 patients, and their neutrophils released higher levels of NETs. Notably, we found that viable SARS-CoV-2 can directly induce the release of NETs by healthy neutrophils. Mechanistically, NETs triggered by SARS-CoV-2 depend on angiotensin-converting enzyme 2, serine protease, virus replication, and PAD-4. Finally, NETs released by SARS-CoV-2–activated neutrophils promote lung epithelial cell death in vitro. These results unravel a possible detrimental role of NETs in the pathophysiology of COVID-19. Therefore, the inhibition of NETs represents a potential therapeutic target for COVID-19.

scholarly journals Neutrophil extracellular traps in cancer: not only catching microbes

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Livia Ronchetti ◽  
Nouha Setti Boubaker ◽  
Maddalena Barba ◽  
Patrizia Vici ◽  
Aymone Gurtner ◽  
...  
Keyword(s):  
Cancer Patients ◽  
White Blood Cells ◽  
Neutrophil Extracellular Traps ◽  
Neutrophil Extracellular Trap ◽  
Prognostic Role ◽  
Extracellular Traps ◽  
Activated Neutrophils ◽  
Neoplastic Process ◽  
Review Current

AbstractNeutrophils are the most abundant type of white blood cells circulating throughout the bloodstream and are often considered the frontline defenders in innate immunity. However, neutrophils are increasingly being recognized as having an important role in tumorigenesis and carcinogenesis due to their aberrant activation by molecules released into the tumor microenvironment. One defensive response of neutrophils that is aberrantly triggered during the neoplastic process is called NETosis, where activated neutrophils expel their DNA and intracellular contents in a web-like structure known as a neutrophil extracellular trap (NET). In cancer, NETosis has been linked to increased disease progression, metastasis, and complications such as venous thromboembolism. NET structures released by neutrophils can also serve as a scaffold for clot formation, shining new light on the role of neutrophils and NETosis in coagulation-mediated diseases.Here, we review current available knowledge regarding NET and the related NETosis process in cancer patients, with an emphasis on pre-clinical and clinical data fostering the identification and validation of biomarkers of NET with a predictive/prognostic role in cancer patients treated with immunotherapy agents. NETosis biomarkers, e.g., citH3, may integrate correlates of immunogenicity currently available (e.g., PD-L1 expression, TMB, TILs) and help select the subsets of patients who may most benefit from the use of the therapeutic weapons under discussion.

scholarly journals Neutrophil Extracellular Traps Affecting Cardiovascular Health in Infectious and Inflammatory Diseases

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1689
Author(s):  
Manovriti Thakur ◽  
Bryce Evans ◽  
Marc Schindewolf ◽  
Iris Baumgartner ◽  
Yvonne Döring
Keyword(s):  
Cardiovascular Health ◽  
Viral Infections ◽  
Inflammatory Diseases ◽  
Vascular Inflammation ◽  
Neutrophil Extracellular Traps ◽  
Immune Defense ◽  
Future Research ◽  
Extracellular Traps ◽  
Infection And Inflammation

Neutrophil extracellular traps (NETs) are web-like structures of decondensed extracellular chromatin fibers and neutrophil granule proteins released by neutrophils. NETs participate in host immune defense by entrapping pathogens. They are pro-inflammatory in function, and they act as an initiator of vascular coagulopathies by providing a platform for the attachment of various coagulatory proteins. NETs are diverse in their ability to alter physiological and pathological processes including infection and inflammation. In this review, we will summarize recent findings on the role of NETs in bacterial/viral infections associated with vascular inflammation, thrombosis, atherosclerosis and autoimmune disorders. Understanding the complex role of NETs in bridging infection and chronic inflammation as well as discussing important questions related to their contribution to pathologies outlined above may pave the way for future research on therapeutic targeting of NETs applicable to specific infections and inflammatory disorders.

scholarly journals The Role of Src Kinase in Macrophage-Mediated Inflammatory Responses

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
Se Eun Byeon ◽  
Young-Su Yi ◽  
Jueun Oh ◽  
Byong Chul Yoo ◽  
Sungyoul Hong ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Immune Responses ◽  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Src Kinase ◽  
Multiple Roles ◽  
Cellular Migration ◽  
Pharmaceutical Drugs ◽  
Tyrosine Protein Kinase

Src kinase (Src) is a tyrosine protein kinase that regulates cellular metabolism, survival, and proliferation. Many studies have shown that Src plays multiple roles in macrophage-mediated innate immunity, such as phagocytosis, the production of inflammatory cytokines/mediators, and the induction of cellular migration, which strongly implies that Src plays a pivotal role in the functional activation of macrophages. Macrophages are involved in a variety of immune responses and in inflammatory diseases including rheumatoid arthritis, atherosclerosis, diabetes, obesity, cancer, and osteoporosis. Previous studies have suggested roles for Src in macrophage-mediated inflammatory responses; however, recently, new functions for Src have been reported, implying that Src functions in macrophage-mediated inflammatory responses that have not been described. In this paper, we discuss recent studies regarding a number of these newly defined functions of Src in macrophage-mediated inflammatory responses. Moreover, we discuss the feasibility of Src as a target for the development of new pharmaceutical drugs to treat macrophage-mediated inflammatory diseases. We provide insights into recent reports regarding new functions for Src that are related to macrophage-related inflammatory responses and the development of novel Src inhibitors with strong immunosuppressive and anti-inflammatory properties, which could be applied to various macrophage-mediated inflammatory diseases.

Social Stressors, Arboviral Infection, and Immune Dysregulation in the Coastal Lowland Region of Ecuador: A Mixed Methods Approach in Ecological Perspective

2021 ◽  
Author(s):  
Denisse Vega Ocasio ◽  
Anna M. Stewart-Ibarra ◽  
Rachel Sippy ◽  
Christina Li ◽  
Kaitlyn McCue ◽  
...  
Keyword(s):  
At Risk ◽  
Immune Responses ◽  
Inflammatory Responses ◽  
Social Stressors ◽  
Biological Responses ◽  
Distress Symptoms ◽  
Tnf Α ◽  
Hair Samples ◽  
Arboviral Diseases

Aedes aegypti, the mosquito that transmits arboviral diseases such as dengue (DENV), chikungunya (CHIKV), and Zika viruses (ZIKV), is present in tropical and subtropical regions of the world. Individuals at risk of mosquito-borne disease (MBD) in the urban tropics face daily challenges linked to their socio-environment conditions, such as poor infrastructure, poverty, crowding, and limited access to adequate healthcare. These daily demands induce chronic stress events and dysregulated immune responses. We sought to investigate the role of socio-ecologic risk factors in distress symptoms and their impact on biological responses to MBD in Machala, Ecuador. Between 2017 and 2019, individuals (≥ 18 years) with suspected arbovirus illness (DENV, ZIKV, and CHIKV) from sentinel clinics were enrolled (index cases, N = 28). Cluster investigations of the index case households and people from four houses within a 200-m radius of index home (associate cases, N = 144) were conducted (total N = 172). Hair samples were collected to measure hair cortisol concentration (HCC) as a stress biomarker. Blood samples were collected to measure serum cytokines concentrations of IL-10, IL-8, TNF-α, and TGF-β. Univariate analyses were used to determine the association of socio-health metrics related to perceived stress scores (PSS), HCC, and immune responses. We found that housing conditions influence PSS and HCC levels in individuals at risk of MBD. Inflammatory cytokine distribution was associated with the restorative phase of immune responses in individuals with low-moderate HCC. These data suggest that cortisol may dampen pro-inflammatory responses and influence activation of the restorative phase of immune responses to arboviral infections.

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