scholarly journals The immune response of T cells and therapeutic targets related to regulating the levels of T helper cells after ischaemic stroke

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Tian-Yu Lei ◽  
Ying-Ze Ye ◽  
Xi-Qun Zhu ◽  
Daniel Smerin ◽  
Li-Juan Gu ◽  
...  

AbstractThrough considerable effort in research and clinical studies, the immune system has been identified as a participant in the onset and progression of brain injury after ischaemic stroke. Due to the involvement of all types of immune cells, the roles of the immune system in stroke pathology and associated effects are complicated. Past research concentrated on the functions of monocytes and neutrophils in the pathogenesis of ischaemic stroke and tried to demonstrate the mechanisms of tissue injury and protection involving these immune cells. Within the past several years, an increasing number of studies have elucidated the vital functions of T cells in the innate and adaptive immune responses in both the acute and chronic phases of ischaemic stroke. Recently, the phenotypes of T cells with proinflammatory or anti-inflammatory function have been demonstrated in detail. T cells with distinctive phenotypes can also influence cerebral inflammation through various pathways, such as regulating the immune response, interacting with brain-resident immune cells and modulating neurogenesis and angiogenesis during different phases following stroke. In view of the limited treatment options available following stroke other than tissue plasminogen activator therapy, understanding the function of immune responses, especially T cell responses, in the post-stroke recovery period can provide a new therapeutic direction. Here, we discuss the different functions and temporal evolution of T cells with different phenotypes during the acute and chronic phases of ischaemic stroke. We suggest that modulating the balance between the proinflammatory and anti-inflammatory functions of T cells with distinct phenotypes may become a potential therapeutic approach that reduces the mortality and improves the functional outcomes and prognosis of patients suffering from ischaemic stroke.

2000 ◽  
Vol 2 (9) ◽  
pp. 1-20 ◽  
Author(s):  
Mark Harber ◽  
Anette Sundstedt ◽  
David Wraith

Current immunosuppression protocols, although often effective, are nonspecific and therefore hazardous. Consequently, immunological tolerance that is antigen specific and does not globally depress the patient's immune system has become one of the Holy Grails of immunology. Since the discovery that cytokines have immunomodulatory effects, extensive research has investigated the potential of these molecules to induce and maintain specific immunological tolerance in the context of transplantation, allergy and autoimmunity. In this article, we review the possible mechanisms by which cytokines can modulate the immune response and the animal models that frequently confound the theory that a single cytokine, or group of cytokines, can induce tolerance in a predictable manner. Finally, we discuss the role of cytokines at a paracrine level, particularly in the context of inducing and maintaining antigen-specific, regulatory T cells with the clinical potential to suppress specific immune responses.


2008 ◽  
Vol 3 (4) ◽  
pp. 254-265 ◽  
Author(s):  
P. A. McCombe ◽  
S. J. Read

Inflammatory and immune responses play important roles following ischaemic stroke. Inflammatory responses contribute to damage and also contribute to repair. Injury to tissue triggers an immune response. This is initiated through activation of the innate immune system. In stroke there is microglial activation. This is followed by an influx of lymphocytes and macrophages into the brain, triggered by production of pro-inflammatory cytokines. This inflammatory response contributes to further tissue injury. There is also a systemic immune response to stroke, and there is a degree of immunosuppression that may contribute to the stroke patient's risk of infection. This immunosuppressive response may also be protective, with regulatory lymphocytes producing cytokines and growth factors that are neuroprotective. The specific targets of the immune response after stroke are not known, and the details of the immune and inflammatory responses are only partly understood. The role of inflammation and immune responses after stroke is twofold. The immune system may contribute to damage after stroke, but may also contribute to repair processes. The possibility that some of the immune response after stroke may be neuroprotective is exciting and suggests that deliberate enhancement of these responses may be a therapeutic option.


2018 ◽  
Vol 19 (9) ◽  
pp. 2732 ◽  
Author(s):  
Katrin Neumann ◽  
Birgit Schiller ◽  
Gisa Tiegs

In sterile liver inflammation, danger signals are released in response to tissue injury to alert the immune system; e.g., by activation of the NLRP3 inflammasome. Recently, IL-33 has been identified as a novel type of danger signal or “alarmin”, which is released from damaged and necrotic cells. IL-33 is a pleiotropic cytokine that targets a broad range of immune cells and exhibits pro- and anti-inflammatory properties dependent on the disease. This review summarizes the immunomodulatory roles of the NLRP3 inflammasome and IL-33 in sterile liver inflammation and highlights potential therapeutic strategies targeting these pathways in liver disease.


2020 ◽  
Author(s):  
Bhanwar Lal Puniya ◽  
Robert Moore ◽  
Akram Mohammed ◽  
Rada Amin ◽  
Alyssa La Fleur ◽  
...  

AbstractThe human immune system, which protects against pathogens and diseases, is a complex network of cells and molecules. The effects of complex dynamical interactions of pathogens and immune cells on the immune response can be studied using computational models. However, a model of the entire immune system is still lacking. Here, we developed a comprehensive computational model that integrates innate and adaptive immune cells, cytokines, immunoglobulins, and nine common pathogens from different classes of virus, bacteria, parasites, and fungi. This model was used to investigate the dynamics of the immune system under two scenarios: (1) single infection with pathogens, and (2) various medically relevant pathogen coinfections. In coinfections, we found that the order of infecting pathogens has a significant impact on the dynamics of cytokines and immunoglobulins. Thus, our model provides a tool to simulate immune responses under different dosage of pathogens and their combinations, which can be further extended and used as a tool for drug discovery and immunotherapy. Furthermore, the model provides a comprehensive and simulatable blueprint of the human immune system as a result of the synthesis of the vast knowledge about the network-like interactions of various components of the system.


2019 ◽  
Vol 74 (2) ◽  
pp. 115-124 ◽  
Author(s):  
Carolina Maldonado Galdeano ◽  
Silvia Inés Cazorla ◽  
José María Lemme Dumit ◽  
Eva Vélez ◽  
Gabriela Perdigón

Background: The gastrointestinal tract is one of the most microbiologically active ecosystems that plays a crucial role in the working of the mucosal immune system (MIS). In this ecosystem, the consumed probiotics stimulate the immune system and induce a network of signals mediated by the whole bacteria or their cell wall structure. This review is aimed at describing the immunological mechanisms of probiotics and their beneficial effects on the host. Summary: Once administered, oral probiotic bacteria interact with the intestinal epithelial cells (IECs) or immune cells associated with the lamina propria, through Toll-like receptors, and induce the production of different cytokines or chemokines. Macrophage chemoattractant protein 1, produced by the IECs, sends signals to other immune cells leading to the activation of the MIS, characterized by an increase in immunoglobulin A+ cells of the intestine, bronchus and mammary glands, and the activation of T cells. Specifically, probiotics activate regulatory T cells that release IL-10. Interestingly, probiotics reinforce the intestinal barrier by an increase of the mucins, the tight junction proteins and the Goblet and Paneth cells. Another proposed mechanism of probiotics is the modulation of intestinal microbiota by maintaining the balance and suppressing the growth of potential pathogenic bacteria in the gut. Furthermore, it has been demonstrated that long-term probiotics consumption does not affect the intestinal homeostasis. The viability of probiotics is crucial in the interaction with IECs and macrophages favoring, mainly, the innate immune response. Macrophages and Dendritic cells (DCs) play an important role in this immune response without inducing an inflammatory pattern, just a slight increase in the cellularity of the lamina propria. Besides, as part of the machinery that probiotics activate to protect against different pathogens, an increase in the microbicidal activity of peritoneal and spleen macrophages has been reported. In malnutrition models, such as undernourishment and obesity, probiotic was able to increase the intestinal and systemic immune response. Furthermore, probiotics contribute to recover the histology of both the intestine and the thymus damaged in these conditions. Probiotic bacteria are emerging as a safe and natural strategy for allergy prevention and treatment. Different mechanisms such as the generation of cytokines from activated pro-T-helper type 1, which favor the production of IgG instead of IgE, have been proposed. Key Messages: Probiotic bacteria, their cell walls or probiotic fermented milk have significant effects on the functionality of the mucosal and systemic immune systems through the activation of multiple immune mechanisms.


2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
S. Viganò ◽  
M. Perreau ◽  
G. Pantaleo ◽  
A. Harari

The immune system has evolved to allow robust responses against pathogens while avoiding autoimmunity. This is notably enabled by stimulatory and inhibitory signals which contribute to the regulation of immune responses. In the presence of a pathogen, a specific and effective immune response must be induced and this leads to antigen-specific T-cell proliferation, cytokines production, and induction of T-cell differentiation toward an effector phenotype. After clearance or control of the pathogen, the effector immune response must be terminated in order to avoid tissue damage and chronic inflammation and this process involves coinhibitory molecules. When the immune system fails to eliminate or control the pathogen, continuous stimulation of T cells prevents the full contraction and leads to the functional exhaustion of effector T cells. Several evidences bothin vitroandin vivosuggest that this anergic state can be reverted by blocking the interactions between coinhibitory molecules and their ligands. The potential to revert exhausted or inactivated T-cell responses following selective blocking of their function made these markers interesting targets for therapeutic interventions in patients with persistent viral infections or cancer.


2021 ◽  
Vol 11 ◽  
Author(s):  
Nimisha Mathur ◽  
Syed F. Mehdi ◽  
Manasa Anipindi ◽  
Monowar Aziz ◽  
Sawleha A. Khan ◽  
...  

Sepsis continues to produce widespread inflammation, illness, and death, prompting intensive research aimed at uncovering causes and therapies. In this article, we focus on ghrelin, an endogenous peptide with promise as a potent anti-inflammatory agent. Ghrelin was discovered, tracked, and isolated from stomach cells based on its ability to stimulate release of growth hormone. It also stimulates appetite and is shown to be anti-inflammatory in a wide range of tissues. The anti-inflammatory effects mediated by ghrelin are a result of both the stimulation of anti-inflammatory processes and an inhibition of pro-inflammatory forces. Anti-inflammatory processes are promoted in a broad range of tissues including the hypothalamus and vagus nerve as well as in a broad range of immune cells. Aged rodents have reduced levels of growth hormone (GH) and diminished immune responses; ghrelin administration boosts GH levels and immune response. The anti-inflammatory functions of ghrelin, well displayed in preclinical animal models of sepsis, are just being charted in patients, with expectations that ghrelin and growth hormone might improve outcomes in patients with sepsis.


2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Norbert Gerdes ◽  
Christina Buerger ◽  
Holger Winkels ◽  
Christian Weber ◽  
Esther Lutgens

Atherosclerosis is a lipid driven chronic inflammatory disease of the arterial wall, involving both innate and adaptive immune responses. Specialized immune cells such as monocytes, B cells, T cells and dendritic cells (DCs) contribute to disease progression or control the inflammatory responses. The CD40-CD40L dyad was identified as an efficient modulator of cellular immune responses. CD40 is a member of the tumor necrosis factor receptor (TNFR) superfamily and is activated by CD40 ligand (CD40L). CD40 and CD40L both are expressed on the majority of immune and non-immune cells associated with atherosclerosis. However, the specific contribution of CD40-CD40L signaling on the different single cell types towards atherosclerosis progression remains undefined. Here, we aimed to investigate the cell type-specific mechanisms of CD40-CD40L interactions in atherosclerosis by generating mice with a conditional ablation of CD40L on T cells. Hyperlipidemic mice with a T cell-specific deficiency of CD40L developed significantly smaller atherosclerotic lesions in the ascending after 28 weeks of chow diet, and following 6 weeks of a cholesterol-enriched diet when compared to their littermate controls. Changes in lesion size were accompanied by a modified anti-inflammatory plaque phenotype, characterized by an increased proportion of smooth muscle cells and a reduced number of pro-inflammatory immune cells, such as macrophages and T cells. T cell CD40L-deficient mice displayed systematically reduced expression of pro-inflammatory cytokines such as IL-1β, IL-2, IL-12, and IFNγ, and increased expression of anti-inflammatory cytokines IL-10 and TGFβ. This anti-inflammatory milieu was paralleled a change in the development and activation status of the T cells with mice lacking CD40L on T cells displaying a reduction in the expression of cytokines and gene markers associated with the activation of T cells (e.g., IL-2, CD69). This change was also reflected within the T cell populations which had a reduced proportion of activated effector T cells and an increased ratio of naïve T cells. Thus, our study ascribes CD40L on T cells a central role in atherosclerosis.


2016 ◽  
Author(s):  
Quentin Marcou ◽  
Irit Carmi-Levy ◽  
Coline Trichot ◽  
Vassili Soumelis ◽  
Thierry Mora ◽  
...  

Cells of the immune system are confronted with opposing pro-and anti-inflammatory signals. Dendritic cells (DC) integrate these cues to make informed decisions whether to initiate an immune response. Confronted with exogenous microbial stimuli, DC endogenously produce both anti-(IL-10) and pro-inflammatory (TNFα) cues whose joint integration controls the cell's final decision. We combine experimental measurements with theoretical modeling to quantitatively describe the integration mode of these opposing signals. We propose a two step integration model that modulates the effect of the two types of signals: an initial bottleneck integrates both signals (IL-10 and TNFα), the output of which is later modulated by the anti-inflammatory signal. We show that the anti-inflammatory IL-10 signaling is long ranged, as opposed to the short-ranged pro-inflammatory TNFα signaling. The model suggests that the population averaging and modulation of the pro-inflammatory response by the anti-inflammatory signal is a safety guard against excessive immune responses.


2020 ◽  
Vol 9 (1) ◽  
pp. 60
Author(s):  
Putu Oky ari Tania

Candidiasis is an infection caused by fungal Candida albicans. The incidence of candidiasis is pretty high in Indonesia. Candida albicans develop their pathogenicity by several ways so that it can invade and escape from the immune system. The host’s immune system must always be vigilant to recognized antigen through various receptors, activation of the transduction pathway and activation of various immune cells. But as organisms that struggle to survive, Candida also develops mechanisms to escape the immune response. There are so many articles have written the immune response against candidiasis, this review aims to understand more and updating information about the biological processes of pathogenicity of fungi and the mechanism of Candida albicans in escaping immune responses, the role of each innate molecule and immune cell, and clinical aspect to Candida albicans infections. We already facing the big challenges against therapy of fungal infection, so by understanding the escape mechanism of Candida albicans, it is possible to developed antifungal or Candida vaccine in the future, therefore the incidence of candidiasis can be suppressed.


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