scholarly journals Role of C5 Activation Products in Sepsis

2010 ◽  
Vol 10 ◽  
pp. 2395-2402 ◽  
Author(s):  
Peter A. Ward
Keyword(s):  
Multiorgan Failure ◽  
Cecal Ligation ◽  
Membrane Attack Complex ◽  
Lymphoid Cells ◽  
Immune Functions ◽  
Human Sepsis ◽  
Activation Products ◽  
C5a Anaphylatoxin

Complement activation products are known to be generated in the setting of both experimental and human sepsis. C5 activation products (C5a anaphylatoxin and the membrane attack complex [MAC] C5b-9) are generated during sepsis following infusion of endotoxin, or after cecal ligation and puncture (CLP), which produces polymicrobial sepsis. C5a reacts with its receptors C5aR and C5L2 in a manner that creates the “cytokine storm”, and is associated with development of multiorgan failure (MOF). A number of other complications arising from the interaction of C5a with its receptors include apoptosis of lymphoid cells, loss of innate immune functions of neutrophils (PMNs, polymorphonuclear leukocytes), cardiomyopathy, disseminated intravascular coagulation, and complications associated with MOF. Neutralization of C5ain vivoor absence/blockade of C5a receptors greatly reduces the adverse events in the setting of sepsis, markedly attenuates MOF, and greatly improves survival. Regarding the possible role of C5b-9 in sepsis, the literature is conflicting. Some studies suggest that C5b-9 is protective, while other studies suggest the contrary. Clearly, in human sepsis, C5a and its receptors may be logical targets for interception.

scholarly journals Manipulation of the Complement System for Benefit in Sepsis

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Peter A. Ward ◽  
Ren-Feng Guo ◽  
Niels C. Riedemann
Keyword(s):  
Septic Shock ◽  
Complement System ◽  
Neutralizing Antibodies ◽  
Multiorgan Failure ◽  
Cecal Ligation ◽  
Lymphoid Cells ◽  
Therapeutic Blockade ◽  
Sepsis And Septic Shock ◽  
The Complement System

There is evidence in sepsis, both in rodents and in humans, that activation of the complement system results in excessive production of C5a, which triggers a series of events leading to septic shock, multiorgan failure, and lethality. In rodents following cecal ligation and puncture (CLP), which induces polymicrobial sepsis, in vivo blockade of C5a using neutralizing antibodies dramatically improved survival, reduced apoptosis of lymphoid cells, and attenuated the ensuing coagulopathy. Based on these data, it seems reasonable to consider therapeutic blockade of C5a in humans entering into sepsis and septic shock. Strategies for the development of such an antibody for use in humans are presented.

scholarly journals Dual Role of Interleukin-10 in Murine NZB/W F1 Lupus

2021 ◽  
Vol 22 (3) ◽  
pp. 1347
Author(s):  
Anaïs Amend ◽  
Natalie Wickli ◽  
Anna-Lena Schäfer ◽  
Dalina T. L. Sprenger ◽  
Rudolf A. Manz ◽  
...  
Keyword(s):  
B Cell ◽  
Disease Model ◽  
Interleukin 10 ◽  
Immune Functions ◽  
Murine Lupus ◽  
Anti Inflammatory ◽  
In Vivo Effects

As a key anti-inflammatory cytokine, IL-10 is crucial in preventing inflammatory and autoimmune diseases. However, in human and murine lupus, its role remains controversial. Our aim was to understand regulation and immunologic effects of IL-10 on different immune functions in the setting of lupus. This was explored in lupus-prone NZB/W F1 mice in vitro and vivo to understand IL-10 effects on individual immune cells as well as in the complex in vivo setting. We found pleiotropic IL-10 expression that largely increased with progressing lupus, while IL-10 receptor (IL-10R) levels remained relatively stable. In vitro experiments revealed pro- and anti-inflammatory IL-10 effects. Particularly, IL-10 decreased pro-inflammatory cytokines and slowed B cell proliferation, thereby triggering plasma cell differentiation. The frequent co-expression of ICOS, IL-21 and cMAF suggests that IL-10-producing CD4 T cells are important B cell helpers in this context. In vitro and in vivo effects of IL-10 were not fully concordant. In vivo IL-10R blockade slightly accelerated clinical lupus manifestations and immune dysregulation. Altogether, our side-by-side in vitro and in vivo comparison of the influence of IL-10 on different aspects of immunity shows that IL-10 has dual effects. Our results further reveal that the overall outcome may depend on the interplay of different factors such as target cell, inflammatory and stimulatory microenvironment, disease model and state. A comprehensive understanding of such influences is important to exploit IL-10 as a therapeutic target.

scholarly journals The Inhibition of Group II Innate Lymphoid Cell Response by IL-27 in Allergic Rhinitis

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Xi Luo ◽  
Qingxiang Zeng ◽  
Yan Li ◽  
Yiquan Tang ◽  
Wenlong Liu ◽  
...  
Keyword(s):  
Allergic Rhinitis ◽  
Tritiated Thymidine ◽  
Lymphoid Cells ◽  
Enzyme Linked Immunosorbent Assay ◽  
Th2 Response ◽  
Group Ii ◽  
New Treatment ◽  
And Function

Objectives. Interleukin-27 (IL-27) has been reported to inhibit type 2 T helper cell (Th2) response in allergic rhinitis (AR). However, its effects on group II innate lymphoid cells (ILC2) in AR are not fully understood. Methods. Nineteen patients with AR and nineteen controls were enrolled in this study. The effects of IL-27 on ILC2 differentiation and function as well as the regulation of the IL-27 receptor (IL-27R) were analyzed by tritiated thymidine incorporation, enzyme-linked immunosorbent assay (ELISA), and real-time polymerase chain reaction (PCR), respectively. AR mice were used to confirm the role of IL-27 in vivo. Results. The serum IL-27 protein expression in AR patients was significantly lower compared with controls. IL-27 decreased the ILC2 proliferation and type II cytokine secretion through the interaction with IL-27R. IL-27 also inhibited systemic and nasal ILC2 response of AR mice. Conclusion. IL-27 inhibited the proliferation and function of ILC2 in AR, implying that IL-27 may be used as new treatment target in AR.

Liver X Receptor Activation Impairs Neutrophil Functions and Aggravates Sepsis

2019 ◽  
Vol 221 (9) ◽  
pp. 1542-1553 ◽  
Author(s):  
Fabrício O Souto ◽  
Fernanda V S Castanheira ◽  
Silvia C Trevelin ◽  
Braulio H F Lima ◽  
Guilherme Cesar Martelossi Cebinelli ◽  
...  
Keyword(s):  
Multiorgan Failure ◽  
Bacterial Load ◽  
Cecal Ligation ◽  
Neutrophil Infiltration ◽  
Receptor Activation ◽  
Messenger Ribonucleic Acid ◽  
X Receptors ◽  
Lxr Agonists

Abstract Background Liver X receptors (LXRs) are nuclear receptors activated by oxidized lipids and were previously implicated in several metabolic development and inflammatory disorders. Although neutrophils express both LXR-α and LXR-β, the consequences of their activation, particularly during sepsis, remain unknown. Methods We used the model of cecal ligation and puncture (CLP) to investigate the role of LXR activation during sepsis. Results In this study, we verified that LXR activation reduces neutrophil chemotactic and killing abilities in vitro. Mice treated with LXR agonists showed higher sepsis-induced mortality, which could be associated with reduced neutrophil infiltration at the infectious foci, increased bacteremia, systemic inflammatory response, and multiorgan failure. In contrast, septic mice treated with LXR antagonist showed increased number of neutrophils in the peritoneal cavity, reduced bacterial load, and multiorgan dysfunction. More important, neutrophils from septic patients showed increased ABCA1 messenger ribonucleic acid levels (a marker of LXR activation) and impaired chemotactic response toward CXCL8 compared with cells from healthy individuals. Conclusions Therefore, our findings suggest that LXR activation impairs neutrophil functions, which might contribute to poor sepsis outcome.

scholarly journals Murine eosinophils labeled with indium-111 oxine: localization to delayed hypersensitivity reactions against a schistosomal antigen and to lymphokine in vivo

Blood ◽  
1983 ◽  
Vol 61 (4) ◽  
pp. 732-739 ◽  
Author(s):  
TH Rand ◽  
JA Clanton ◽  
V Runge ◽  
D English ◽  
DG Colley
Keyword(s):  
Lymphoid Cells ◽  
Hypersensitivity Reactions ◽  
Cell Type ◽  
Tissue Samples ◽  
Eosinophil Migration ◽  
Intradermal Administration ◽  
Indium 111 ◽  
Eosinophil Involvement

Abstract We have evaluated a method for quantitation of eosinophil migration to stimuli in vivo. Upon transfusion into normal syngeneic mice, 111In- labeled eosinophils had an intravascular half-life of 9.5 hr and distributed predominantly into spleen, bone marrow, and liver. In either Schistosoma mansoni-infected mice or recipients of lymphoid cells from infected mice, intradermal (ear pinna) injection of the schistosomal egg antigenic preparation (SEA) elicited time-dependent accumulation of 111In-labeled eosinophils detectable by either gamma scintillation counting of tissue samples or by nuclear medicine external imaging. Intradermal administration of a lymphokine fraction (containing eosinophil stimulation promoter activity) similarly caused accumulation of 111In-labeled eosinophils. Both reactions depended on the concentration of stimulus (SEA or lymphokine). 111In-labeled neutrophils or macrophages or 125I-albumin did not preferentially accumulate at the reactions examined to the extent found with 111In- labeled eosinophils, indicating that localization of label depends on an active process and is due to eosinophils rather than a contaminating cell type. The method was used to estimate how long eosinotactic lymphokine remained at dermal sites: 60% of initial activity was present 12 hr after injection. The model is discussed with regard to the role of lymphokines in hypersensitivity reactions with eosinophil involvement, such as the granulomatous response to S. mansoni eggs.

scholarly journals Toll-like receptor 9 inhibition reduces mortality in polymicrobial sepsis

2008 ◽  
Vol 205 (6) ◽  
pp. 1277-1283 ◽  
Author(s):  
George Plitas ◽  
Bryan M. Burt ◽  
Hoang M. Nguyen ◽  
Zubin M. Bamboat ◽  
Ronald P. DeMatteo
Keyword(s):  
Immune Response ◽  
Critical Role ◽  
Cecal Ligation ◽  
High Rate ◽  
Microbial Pathogens ◽  
Lower Serum ◽  
Human Sepsis ◽  
Cytokine Levels ◽  
Potential Strategy

The high rate of mortality in patients with sepsis results from an inappropriately amplified systemic inflammatory response to infection. Toll-like receptors (TLRs) are important for the activation of innate immunity against microbial pathogens. We demonstrate a critical role of TLR9 in the dysregulated immune response and death associated with sepsis. Compared with wild-type (WT) mice, TLR9−/− mice exhibited lower serum inflammatory cytokine levels, higher bacterial clearance, and greater survival after experimental peritonitis induced by cecal ligation and puncture (CLP). Protection of TLR9−/− mice after CLP was associated with a greater number of peritoneal dendritic cells (DCs) and granulocytes than in WT controls. Adoptive transfer of TLR9−/− DCs was sufficient to protect WT mice from CLP and increased the influx of peritoneal granulocytes. Subsequent experiments with a depleting antibody revealed that granulocytes were required for survival in TLR9−/− mice. Remarkably, a single injection of an inhibitory CpG sequence that blocks TLR9 protected WT mice, even when administered as late as 12 h after CLP. Our findings demonstrate that the detrimental immune response to bacterial sepsis occurs via TLR9 stimulation. TLR9 blockade is a potential strategy for the treatment of human sepsis.

scholarly journals Role of Complement in Multiorgan Failure

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Daniel Rittirsch ◽  
Heinz Redl ◽  
Markus Huber-Lang
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Inflammatory Response ◽  
Complement System ◽  
Multiorgan Failure ◽  
Severe Trauma ◽  
Organ Systems ◽  
Activation Products ◽  
The Complement System

Multiorgan failure (MOF) represents the leading cause of death in patients with sepsis and systemic inflammatory response syndrome (SIRS) following severe trauma. The underlying immune response is highly complex and involves activation of the complement system as a crucial entity of innate immunity. Uncontrolled activation of the complement system during sepsis and SIRS with in excessive generation of complement activation products contributes to an ensuing dysfunction of various organ systems. In the present review, mechanisms of the inflammatory response in the development of MOF in sepsis and SIRS with particular focus on the complement system are discussed.

scholarly journals Iron, copper and immunocompetence

2007 ◽  
Vol 98 (S1) ◽  
pp. S24-S28 ◽  
Author(s):  
Carlos Muñoz ◽  
Ernesto Rios ◽  
Jorge Olivos ◽  
Oscar Brunser ◽  
Manuel Olivares
Keyword(s):  
Cell Biology ◽  
Respiratory Infections ◽  
The Elderly ◽  
Iron Nutrition ◽  
Immune Functions ◽  
Human Beings ◽  
Additional Information

Microminerals including copper and iron are essential to immunity and health in human beings. The development of powerful tools in analytical cell biology and molecular genetics has facilitated efforts to identify specific cellular and molecular functions of trace elements in the maturation, activation and functions of host defence mechanisms. Selected recent reports about the role of copper and iron nutrition on immune functions are critically analysed here. Effects of trace element supplementation on infectious morbidity are also reviewed. While micromineral deficiencies, in general, may have widespread effects on nearly all components of immune response, these effects can be reversed by supplementation. However, the conflicting effects of iron deficiency and iron supplementationin vitroon the defensive systems reveals the urgent need for further additional information on thein vivosituation. In the elderly, vaccination against respiratory infections is likely to protect only 30–70 % of the population. However, it may be possible to modulate immune function and ultimately reduce the severity of infections through micronutrient supplementation. Thus, microminerals contribute to the maintenance of the balance between immunity and health in humans.

scholarly journals A CCL1/CCR8-dependent feed-forward mechanism drives ILC2 functions in type 2–mediated inflammation

2019 ◽  
Vol 216 (12) ◽  
pp. 2763-2777 ◽  
Author(s):  
Lisa Knipfer ◽  
Anja Schulz-Kuhnt ◽  
Markus Kindermann ◽  
Vicky Greif ◽  
Cornelia Symowski ◽  
...  
Keyword(s):  
Chemokine Receptor ◽  
Inflammatory Diseases ◽  
Lymphoid Cells ◽  
Immune Functions ◽  
In Vivo Experiments ◽  
Anatomical Compartment ◽  
Group 2

Group 2 innate lymphoid cells (ILC2s) possess indispensable roles during type 2–mediated inflammatory diseases. Although their physiological and detrimental immune functions seem to depend on the anatomical compartment they reside, their tissue tropism and the molecular and immunological processes regulating the self-renewal of the local pool of ILC2s in the context of inflammation or infection are incompletely understood. Here, we analyzed the role of the CC-chemokine receptor CCR8 for the biological functions of ILC2s. In vitro and in vivo experiments indicated that CCR8 is in comparison to the related molecule CCR4 less important for migration of these cells. However, we found that activated mouse and human ILC2s produce the CCR8 ligand CCL1 and are a major source of CCL1 in vivo. CCL1 signaling to ILC2s regulates their proliferation and supports their capacity to protect against helminthic infections. In summary, we identify a novel chemokine receptor–dependent mechanism by which ILC2s are regulated during type 2 responses.

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