The role of platelets in inflammation

2015 ◽  
Vol 114 (09) ◽  
pp. 449-458 ◽  
Author(s):  
Robert Storey ◽  
Mark Thomas

SummaryThere is growing recognition of the critical role of platelets in inflammation and immune responses. Recent studies have indicated that antiplatelet medications may reduce mortality from infections and sepsis, which suggests possible clinical relevance of modifying platelet responses to inflammation. Platelets release numerous inflammatory mediators that have no known role in haemostasis. Many of these mediators modify leukocyte and endothelial responses to a range of different inflammatory stimuli. Additionally, platelets form aggregates with leukocytes and form bridges between leukocytes and endothelium, largely mediated by platelet P-selectin. Through their interactions with monocytes, neutrophils, lymphocytes and the endothelium, platelets are therefore important coordinators of inflammation and both innate and adaptive immune responses.

Genes ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 323 ◽  
Author(s):  
Guoying Wang ◽  
Xianghui Li ◽  
Lei Zhang ◽  
Abualgasim Elgaili Abdalla ◽  
Tieshan Teng ◽  
...  

Dendritic cells (DCs) play a critical role in the immune system which sense pathogens and present their antigens to prime the adaptive immune responses. As the progression of sepsis occurs, DCs are capable of orchestrating the aberrant innate immune response by sustaining the Th1/Th2 responses that are essential for host survival. Hence, an in-depth understanding of the characteristics of DCs would have a beneficial effect in overcoming the obstacle occurring in sepsis. This paper focuses on the role of DCs in the progression of sepsis and we also discuss the reverse sepsis-induced immunosuppression through manipulating the DC function. In addition, we highlight some potent immunotherapies that could be used as a novel strategy in the early treatment of sepsis.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Anna Cláudia Calvielli Castelo Branco ◽  
Fábio Seiti Yamada Yoshikawa ◽  
Anna Julia Pietrobon ◽  
Maria Notomi Sato

Inflammatory mediators, including cytokines, histamine, bradykinin, prostaglandins, and leukotrienes, impact the immune system, usually as proinflammatory factors. Other mediators act as regulatory components to establish homeostasis after injury or prevent the inflammatory process. Histamine, a biogenic vasoactive amine, causes symptoms such as allergies and has a pleiotropic effect that is dependent on its interaction with its four histamine receptors. In this review, we discuss the dualistic effects of histamine: how histamine affects inflammation of the immune system through the activation of intracellular pathways that induce the production of inflammatory mediators and cytokines in different immune cells and how histamine exerts regulatory functions in innate and adaptive immune responses. We also evaluate the interactions between these effects.


2012 ◽  
Vol 181 (5) ◽  
pp. 1607-1620 ◽  
Author(s):  
Rainer Krebs ◽  
Jussi M. Tikkanen ◽  
Jussi O. Ropponen ◽  
Michael Jeltsch ◽  
Janne J. Jokinen ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Zhiheng Xu ◽  
Yuanyuan Yang ◽  
Jianmeng Zhou ◽  
Yongbo Huang ◽  
Ya Wang ◽  
...  

Background. Calreticulin has been identified to play a critical role in innate and adaptive immune responses. However, little is known about the role of calreticulin in sepsis with a characteristic of immune disorder. This study was aimed at investigating whether plasma calreticulin level increases in sepsis and its association with sepsis severity. Methods. This retrospective analysis evaluated sepsis patients who were admitted to the intensive care unit (ICU). Healthy subjects were also included as controls. Plasma samples were collected from the patients within 48 h after ICU admission as well as the healthy subjects. Plasma calreticulin levels were measured via the enzyme-linked immunosorbent assay. Results. In total, 127 sepsis patients and 40 healthy controls were included. Calreticulin was significantly increased in sepsis patients than in healthy controls. Furthermore, the level of plasma calreticulin was significantly higher in nonsurvivors than in survivors. Patients with calreticulin levels>343.5 pg/ml showed lower cumulative survival than those with levels<343.5 pg/ml. Conclusion. Calreticulin level was positively correlated with the severity of sepsis. High calreticulin level indicated poor prognosis of sepsis patients.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Dragana Odobasic ◽  
A. Richard Kitching ◽  
Stephen R. Holdsworth

Neutrophils are no longer seen as leukocytes with a sole function of being the essential first responders in the removal of pathogens at sites of infection. Being armed with numerous pro- and anti-inflammatory mediators, these phagocytes can also contribute to the development of various autoimmune diseases and can positively or negatively regulate the generation of adaptive immune responses. In this review, we will discuss how myeloperoxidase, the most abundant neutrophil granule protein, plays a key role in the various functions of neutrophils in innate and adaptive immunity.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Killen García ◽  
Gisselle Escobar ◽  
Pablo Mendoza ◽  
Caroll Beltran ◽  
Claudio Perez ◽  
...  

Neisseria gonorrhoeae(Ngo) has developed multiple immune evasion mechanisms involving the innate and adaptive immune responses. Recent findings have reported that Ngo reduces the IL-1βsecretion of infected human monocyte-derived macrophages (MDM). Here, we investigate the role of adenosine triphosphate (ATP) in production and release of IL-1βin Ngo-infected MDM. We found that the exposure of Ngo-infected MDM to ATP increases IL-1βlevels about ten times compared with unexposed Ngo-infected MDM (P<0.01). However, we did not observe any changes in inflammasome transcriptional activation of speck-like protein containing a caspase recruitment domain (CARD) (ASC,P>0.05) and caspase-1 (CASP1,P>0.05). In addition, ATP was not able to modify caspase-1 activity in Ngo-infected MDM but was able to increase pyroptosis (P>0.01). Notably ATP treatment defined an increase of positive staining for IL-1βwith a distinctive intracellular pattern of distribution. Collectively, these data demonstrate that ATP induces IL-1βsecretion by a mechanism not related to the NLRP3/ASC/caspase-1 axis and likely is acting at the level of vesicle trafficking or pore formation.


2003 ◽  
Vol 9 (1) ◽  
pp. 7-10 ◽  
Author(s):  
Naoko Aoki ◽  
Shoji Kimura ◽  
Zhou Xing

2011 ◽  
Vol 11 ◽  
pp. 2418-2423 ◽  
Author(s):  
Hoda Hassan ◽  
Amal O. Amer

The role of apoptosis-associated speck-Like protein (ASC) in the assembly of the inflammasome complex within macrophages has been elucidated in several studies. In this particular role, ASC functions as an adaptor protein by linking nod-like receptors (NLRs) and procaspase-1, thereby leading to the activation of caspase-1 to cleave inflammatory cytokines IL-1βand IL-18 and inducing pyroptosis. It has been noted that ASC maintains inflammasome-independent roles, including but not limited to controlling the expression of Dock2 and mitogen-activated protein kinases (MAPK/ERK2) and regulating the NF-κB pathway. This paper will emphasize the major roles of ASC during pathogen infection, the mechanisms by which it mediates inflammation, and discuss its more recently discovered functions.


2010 ◽  
Vol 84 (13) ◽  
pp. 6549-6563 ◽  
Author(s):  
Erin L. Lousberg ◽  
Cara K. Fraser ◽  
Michael G. Tovey ◽  
Kerrilyn R. Diener ◽  
John D. Hayball

ABSTRACT Type I interferons (IFNs) are considered to be important mediators of innate immunity due to their inherent antiviral activity, ability to drive the transcription of a number of genes involved in viral clearance, and their role in the initiation of innate and adaptive immune responses. Due to the central role of type I IFNs, we sought to determine their importance in the generation of immunity to a recombinant vaccine vector fowlpox virus (FPV). In analyzing the role of type I IFNs in immunity to FPV, we show that they are critical to the secretion of a number of innate and proinflammatory cytokines, including type I IFNs themselves as well as interleukin-12 (IL-12), tumor necrosis factor-alpha (TNF-α), IL-6, and IL-1β, and that deficiency leads to enhanced virus-mediated antigen expression. Interestingly, however, type I IFNs were not required for adaptive immune responses to recombinant FPV even though plasmacytoid dendritic cells (pDCs), the primary producers of type I IFNs, have been shown to be requisite for this to occur. Furthermore, we provide evidence that the importance of pDCs may lie in their ability to capture and present virally derived antigen to T cells rather than in their capacity as professional type I IFN-producing cells.


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