Immune and Inflammatory Responses to Stroke: Good Or Bad?

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.

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.


2019 ◽  
Vol 41 (1) ◽  
pp. 36-41 ◽  
Author(s):  
Simon Spichak ◽  
Timothy G. Dinan ◽  
John F. Cryan

How does the immune system impact brain development? The exciting and somewhat unexpected relationship between the immune system and the brain has become one of the most fascinating topics in neuroscience. Even though the immune system was initially implicated in resolving viral and bacterial threats, it is now becoming more evident that it also plays a role in processes in the brain, both under healthy and pathological conditions. This novel role of the immune system in brain health has been implicated in various psychopathologies where neurodevelopment, stress and mood are central. In particular, its role in healthy brain development is becoming more evident, and understanding neuroimmune communication is becoming crucial in treating neurodevelopmental and mood disorders in later life. In the brain, glia function as part of the innate immune system and are programmed to respond to pathogens and physical injury. They also play an important role in neuronal development and pruning. These cells communicate with and respond to chemical signals, such as cytokines and chemokines, which can then initiate or downregulate inflammatory responses. Finally, the trillions of microbes residing in the gut can also stimulate cytokine and chemokine responses in the periphery and play an important role in both immunity and brain development.


2018 ◽  
Vol 8 (1) ◽  
pp. 194-201
Author(s):  
KM. Terlikowska ◽  
MA. Strzyż-Skalij ◽  
K. Kryński ◽  
M. Osmólska ◽  
Z. Łada ◽  
...  

Ovarian cancer is the most threatening cause of death among gynecologic malignancies and represents the fifth leading cause of death from all cancers for women. Research reveals that ovarian cancer patients exhibit significant immune responses against the tumor. In this review of the current literature chiefly the interaction of ovarian cancer tumor cells and the immune system is discussed. There is increasingly growing evidence that pro-inflammatory cytokines are involved in intricate complex of mechanisms responsible for tumorigenesis, and delicate balance between pro- and anti-inflammatory cytokines is critical for the antitumor host immune response.


2021 ◽  
Vol 36 (3) ◽  
Author(s):  
Anjali Bhat ◽  
Thomas Parr ◽  
Maxwell Ramstead ◽  
Karl Friston

AbstractThere is a steadily growing literature on the role of the immune system in psychiatric disorders. So far, these advances have largely taken the form of correlations between specific aspects of inflammation (e.g. blood plasma levels of inflammatory markers, genetic mutations in immune pathways, viral or bacterial infection) with the development of neuropsychiatric conditions such as autism, bipolar disorder, schizophrenia and depression. A fundamental question remains open: why are psychiatric disorders and immune responses intertwined? To address this would require a step back from a historical mind–body dualism that has created such a dichotomy. We propose three contributions of active inference when addressing this question: translation, unification, and simulation. To illustrate these contributions, we consider the following questions. Is there an immunological analogue of sensory attenuation? Is there a common generative model that the brain and immune system jointly optimise? Can the immune response and psychiatric illness both be explained in terms of self-organising systems responding to threatening stimuli in their external environment, whether those stimuli happen to be pathogens, predators, or people? Does false inference at an immunological level alter the message passing at a psychological level (or vice versa) through a principled exchange between the two systems?


2021 ◽  
Vol 22 (21) ◽  
pp. 11898
Author(s):  
Miguel Angel Galván Morales ◽  
Josaphat Miguel Montero-Vargas ◽  
Juan Carlos Vizuet-de-Rueda ◽  
Luis M. Teran

Programmed cell death 1 (PD-1) and its ligands PD-L1 and PD-L2 are receptors that act in co-stimulatory and coinhibitory immune responses. Signaling the PD-1/PD-L1 or PD-L2 pathway is essential to regulate the inflammatory responses to infections, autoimmunity, and allergies, and it has been extensively studied in cancer. Allergic diseases include asthma, rhinoconjunctivitis, atopic dermatitis, drug allergy, and anaphylaxis. These overactive immune responses involve IgE-dependent activation and increased CD4+ T helper type 2 (Th2) lymphocytes. Recent studies have shown that PD-L1 and PD-L2 act to regulate T-cell activation and function. However, the main role of PD-1 and its ligands is to balance the immune response; however, the inflammatory process of allergic diseases is poorly understood. These immune checkpoint molecules can function as a brake or a kick-start to regulate the adaptive immune response. These findings suggest that PD-1 and its ligands may be a key factor in studying the exaggerated response in hypersensitivity reactions in allergies. This review summarizes the current understanding of the role of PD-1 and PD-L1 and PD-L2 pathway regulation in allergic diseases and how this immunomodulatory pathway is currently being targeted to develop novel therapeutic immunotherapy.


2011 ◽  
Vol 79 (8) ◽  
pp. 2964-2973 ◽  
Author(s):  
Joshua C. Cyktor ◽  
Joanne Turner

ABSTRACTThe generation of an effective immune response against an infection while also limiting tissue damage requires a delicate balance between pro- and anti-inflammatory responses. Interleukin-10 (IL-10) has potent immunosuppressive effects and is essential for regulation of immune responses. However, the immunosuppressive properties of IL-10 can also be exploited by pathogens to facilitate their own survival. In this minireview, we discuss the role of IL-10 in modulating intracellular bacterial, fungal, and parasitic infections. Using information from several different infection models, we bring together and highlight some common pathways for IL-10 regulation and function that cannot be fully appreciated by studies of a single pathogen.


2020 ◽  
Vol 21 (9) ◽  
pp. 3329 ◽  
Author(s):  
Yingzhi Gu ◽  
Xiaozhe Han

Periodontitis is known to be initiated by periodontal microbiota derived from biofilm formation. The microbial dysbiotic changes in the biofilm trigger the host immune and inflammatory responses that can be both beneficial for the protection of the host from infection, and detrimental to the host, causing tissue destruction. During this process, recognition of Pathogen-Associated Molecular Patterns (PAMPs) by the host Pattern Recognition Receptors (PRRs) such as Toll-like receptors (TLRs) play an essential role in the host–microbe interaction and the subsequent innate as well as adaptive responses. If persistent, the adverse interaction triggered by the host immune response to the microorganisms associated with periodontal biofilms is a direct cause of periodontal inflammation and bone loss. A large number of T and B lymphocytes are infiltrated in the diseased gingival tissues, which can secrete inflammatory mediators and activate the osteolytic pathways, promoting periodontal inflammation and bone resorption. On the other hand, there is evidence showing that immune regulatory T and B cells are present in the diseased tissue and can be induced for the enhancement of their anti-inflammatory effects. Changes and distribution of the T/B lymphocytes phenotype seem to be a key determinant of the periodontal disease outcome, as the functional activities of these cells not only shape up the overall immune response pattern, but may directly regulate the osteoimmunological balance. Therefore, interventional strategies targeting TLR signaling and immune regulatory T/B cells may be a promising approach to rebalance the immune response and alleviate bone loss in periodontal disease. In this review, we will examine the etiological role of TLR signaling and immune cell osteoclastogenic activity in the pathogenesis of periodontitis. More importantly, the protective effects of immune regulatory lymphocytes, particularly the activation and functional role of IL-10 expressing regulatory B cells, will be discussed.


2003 ◽  
Vol 5 (3) ◽  
pp. 1-22 ◽  
Author(s):  
Roshni Mitra ◽  
Sarvjeet Singh ◽  
Ashok Khar

The role of the immune system in combating tumour progression has been studied extensively. The two branches of the immune response – humoral and cell-mediated – act both independently and in concert to combat tumour progression, the success of which depends on the immunogenicity of the tumour cells. The immune system discriminates between transformed cells and normal cells by virtue of the presence of unique antigens on tumour cells. Despite this, the immune system is not always able to detect and kill cancerous cells because neoplasms have also evolved various strategies to escape immune surveillance. Attempts are being made to trigger the immune system into an early and efficient response against malignant cells, and various therapeutic modalities are being developed to enhance the strength of the immune response against tumours. This review aims to elucidate the tumouricidal role of various components of the immune system, including macrophages, lymphocytes, dendritic cells and complement.


Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 506
Author(s):  
José Manuel Pérez de la Lastra ◽  
Celia Andrés-Juan ◽  
Francisco J. Plou ◽  
Eduardo Pérez-Lebeña

SARS-CoV-2, the coronavirus triggering the disease COVID-19, has a catastrophic health and socioeconomic impact at a global scale. Three key factors contribute to the pathogenesis of COVID-19: excessive inflammation, immune system depression/inhibition, and a set of proinflammatory cytokines. Common to these factors, a central function of oxidative stress has been highlighted. A diversity of clinical trials focused predominantly on antioxidants are being implemented as potential therapies for COVID-19. In this study, we look at the role of zinc, glutathione, and polyphenols, as key antioxidants of possible medicinal or nutritional significance, and examine their role in the antiviral immune response induced by SARS-Cov-2. An unresolved question is why some people experience chronic COVID and others do not. Understanding the relationship between SARS-CoV-2 and the immune system, as well as the role of defective immune responses to disease development, would be essential to recognize the pathogenesis of COVID-19, the risk factors that affect the harmful consequences of the disease, and the rational design of successful therapies and vaccinations. We expect that our research will provide a novel perspective that contributes to the design of clinical or nutritional targets for the prevention of this pandemic.


Sign in / Sign up

Export Citation Format

Share Document