scholarly journals Ocular Microbiota and Intraocular Inflammation

2020 ◽  
Vol 11 ◽  
Author(s):  
Jing Jing Li ◽  
Sanjun Yi ◽  
Lai Wei

The term ocular microbiota refers to all types of commensal and pathogenic microorganisms present on or in the eye. The ocular surface is continuously exposed to the environment and harbors various commensals. Commensal microbes have been demonstrated to regulate host metabolism, development of immune system, and host defense against pathogen invasion. An unbalanced microbiota could lead to pathogenic microbial overgrowth and cause local or systemic inflammation. The specific antigens that irritate the deleterious immune responses in various inflammatory eye diseases remain obscure, while recent evidence implies a microbial etiology of these illnesses. The purpose of this review is to provide an overview of the literature on ocular microbiota and the role of commensal microbes in several eye diseases. In addition, this review will also discuss the interaction between microbial pathogens and host factors involved in intraocular inflammation, and evaluate therapeutic potential of targeting ocular microbiota to treat intraocular inflammation.

2021 ◽  
Vol 5 (4) ◽  
pp. 195-221
Author(s):  
Katarzyna Nazimek ◽  

<abstract> <p>At present, special efforts are being made to develop the strategies allowing for activation of long-lasting antigen-specific immune tolerance in therapy of allergic and autoimmune diseases. Some of these therapeutic approaches are aimed at modulating cell functions at genetic level by using miRNA-based and miRNA-targeting treatments. Simultaneously, the crucial role of extracellular vesicles as natural miRNA conveyors is highlighted for induction of antigen-specific immune tolerance, especially that they appear to be easily manipulatable for therapeutic applications. Among other immune-related miRNAs, miR-150 is getting special attention as it is differently expressed by immune cells at various stages of their maturation and differentiation. In addition, miR-150 is involved in different signaling cascades orchestrating humoral and cell-mediated mechanisms of both innate and adaptive immune responses. Therefore, miR-150 is considered a master regulator of immunity in mammals. Currently, physiological miR-150-dependent regulatory circuits and causes of their malfunctioning that underlie the pathogenesis of allergic and autoimmune disorders are being unraveled. Thus, present review summarizes the current knowledge of the role of miR-150 in the pathogenesis and complications of these diseases. Furthermore, the involvement of miR-150 in regulation of immune responses to allergens and self-antigens and in induction of antigen-specific immune tolerance is discussed with the special emphasis on the therapeutic potential of this miRNA.</p> </abstract>


2021 ◽  
Vol 28 ◽  
Author(s):  
Adeleh Sahebnasagh ◽  
Fatemeh Saghafi ◽  
Sina Negintaji ◽  
Tingyan Hu ◽  
Mojtaba Shabani-Boroujeni ◽  
...  

: In recent years, there has been an increasing interest in understanding the mysterious functions of nitric oxide (NO) and how this pleiotropic signaling molecule contributes to tumorigenesis. This review attempts to expose and discuss the information available on the immunomodulatory role of NO in cancer and recent approaches to the role of NO donors in the area of immunotherapy. To address the goal, the following databases were searched to identify relevant literature concerning empirical evidence: The Cochrane Library, Pubmed, Medline, EMBASE from 1980 through March 2020. Valuable attempts have been made to develop distinctive NO-based cancer therapy. Although the data do not allow generalization, the evidence seems to indicate that low / moderate levels may favor tumorigenesis while higher levels would exert anti-tumor effects. In this sense, the use of NO donors could have an important therapeutic potential within immunotherapy, although there are still no clinical trials. The emerging understanding of NO-regulated immune responses in cancer may help unravel the recent features of this “double-edged sword” in cancer physiological and pathologic processes and its potential use as a therapeutic agent for cancer treatment. In short, in this review, we discuss the complex cellular mechanism in which NO, as a pleiotropic signaling molecule, participates in cancer pathophysiology. We also debate the dual role of NO in cancer and tumor progression, and clinical approaches for inducible nitric oxide synthase (iNOS) based therapy against cancer.


2020 ◽  
Author(s):  
Richa Mishra ◽  
Sanjana Bhattacharya ◽  
Bhupendra S Rawat ◽  
Ashish Kumar ◽  
Akhilesh Kumar ◽  
...  

AbstractPrecise regulation of innate immunity is crucial for the development of appropriate host immunity against microbial infections and the maintenance of immune homeostasis. The microRNAs are small non-coding RNA, post-transcriptional regulator of multiple genes and act as a rheostat for protein expression. Here, we identified microRNA(miR)-30e-5p (miR-30e) induced by the hepatitis B virus (HBV) and other viruses that act as a master regulator for innate immune responses. Moreover, pegylated type I interferons treatment to HBV patients for viral reduction also reduces the miRNA. Additionally, we have also shown the immuno-pathological effects of miR-30e in systemic lupus erythematous (SLE) patients and SLE mouse model. Mechanistically, the miR-30e targets multiple negative regulators namely TRIM38, TANK, ATG5, ATG12, BECN1, SOCS1, SOCS3 of innate immune signaling pathways and enhances innate immune responses. Furthermore, sequestering of endogenous miR-30e in PBMCs of SLE patients and SLE mouse model respectively by the introduction of antagomir and locked nucleic acid based inhibitor significantly reduces type I interferon and pro-inflammatory cytokines. Collectively, our study demonstrates the novel role of miR-30e in innate immunity and its prognostic and therapeutic potential in infectious and autoimmune diseases.


2019 ◽  
Vol 20 (8) ◽  
pp. 1986 ◽  
Author(s):  
Joana R. Lérias ◽  
Georgia Paraschoudi ◽  
Inês Silva ◽  
João Martins ◽  
Eric de Sousa ◽  
...  

Immune responses to human cytomegalovirus (CMV) can be used to assess immune fitness in an individual. Further to its clinical significance in posttransplantation settings, emerging clinical and translational studies provide examples of immune correlates of protection pertaining to anti-CMV immune responses in the context of cancer or infectious diseases, e.g., tuberculosis. In this viewpoint, we provide a brief overview about CMV-directed immune reactivity and immune fitness in a clinical context and incorporate some of our own findings obtained from peripheral blood or tumour-infiltrating lymphocytes (TIL) from patients with advanced cancer. Observations in patients with solid cancers whose lesions contain both CMV and tumour antigen-specific T-cell subsets are highlighted, due to a possible CMV-associated “bystander” effect in amplifying local inflammation and subsequent tumour rejection. The role of tumour-associated antibodies recognising diverse CMV-derived epitopes is also discussed in light of anti-cancer immune responses. We discuss here the use of anti-CMV immune responses as a theranostic tool—combining immunodiagnostics with a personalised therapeutic potential—to improve treatment outcomes in oncological indications.


2021 ◽  
Vol 22 (2) ◽  
pp. 721
Author(s):  
Youssof Eshac ◽  
Rachel L. Redfern ◽  
Vinay Kumar Aakalu

The ocular surface has the challenging responsibility of maintaining a clear moist refractive surface while protecting the eye from exogenous pathogens and the environment. Homeostasis of the ocular surface, including its innate immune components, is altered in ocular surface disease states. In this review, we focus on antimicrobial peptides and the role they play in the immune response of the ocular surface during healthy states and dry eye diseases. Antimicrobial peptides are of special interest to the study of the ocular surface because of their various roles that include microbial threat neutralization, wound healing, and immune modulation. This review explores current literature on antimicrobial peptides in ocular surface diseases and discusses their therapeutic potential in ocular surface diseases and dry eye.


2021 ◽  
Vol 22 (23) ◽  
pp. 12978
Author(s):  
Heidelinde Sammallahti ◽  
Arto Kokkola ◽  
Sama Rezasoltani ◽  
Reza Ghanbari ◽  
Hamid Asadzadeh Aghdaei ◽  
...  

Pancreatic cancer (PC) is an aggressive disease with a high mortality and poor prognosis. The human microbiome is a key factor in many malignancies, having the ability to alter host metabolism and immune responses and participate in tumorigenesis. Gut microbes have an influence on physiological functions of the healthy pancreas and are themselves controlled by pancreatic secretions. An altered oral microbiota may colonize the pancreas and cause local inflammation by the action of its metabolites, which may lead to carcinogenesis. The mechanisms behind dysbiosis and PC development are not completely clear. Herein, we review the complex interactions between PC tumorigenesis and the microbiota, and especially the question, whether and how an altered microbiota induces oncogenomic changes, or vice versa, whether cancer mutations have an impact on microbiota composition. In addition, the role of the microbiota in drug efficacy in PC chemo- and immunotherapies is discussed. Possible future scenarios are the intentional manipulation of the gut microbiota in combination with therapy or the utilization of microbial profiles for the noninvasive screening and monitoring of PC.


2021 ◽  
Vol 10 (24) ◽  
pp. 5907
Author(s):  
Toru Tanaka ◽  
Naoto Sasaki ◽  
Yoshiyuki Rikitake

Atherosclerotic diseases, including ischemic heart disease and stroke, are a main cause of mortality worldwide. Chronic vascular inflammation via immune dysregulation is critically involved in the pathogenesis of atherosclerosis. Accumulating evidence suggests that regulatory T cells (Tregs), responsible for maintaining immunological tolerance and suppressing excessive immune responses, play an important role in preventing the development and progression of atherosclerosis through the regulation of pathogenic immunoinflammatory responses. Several strategies to prevent and treat atherosclerosis through the promotion of regulatory immune responses have been developed, and could be clinically applied for the treatment of atherosclerotic cardiovascular disease. In this review, we summarize recent advances in our understanding of the protective role of Tregs in atherosclerosis and discuss attractive approaches to treat atherosclerotic disease by augmenting regulatory immune responses.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaoling Wang ◽  
Jianwei Chen ◽  
Jun Xu ◽  
Jun Xie ◽  
David C. H. Harris ◽  
...  

The phenotypic heterogeneity and functional diversity of macrophages confer on them complexed roles in the development and progression of kidney diseases. After kidney injury, bone marrow-derived monocytes are rapidly recruited to the glomerulus and tubulointerstitium. They are activated and differentiated on site into pro-inflammatory M1 macrophages, which initiate Th1-type adaptive immune responses and damage normal tissues. In contrast, anti-inflammatory M2 macrophages induce Th2-type immune responses, secrete large amounts of TGF-β and anti-inflammatory cytokines, transform into αSMA+ myofibroblasts in injured kidney, inhibit immune responses, and promote wound healing and tissue fibrosis. Previous studies on the role of macrophages in kidney fibrosis were mainly focused on inflammation-associated injury and injury repair. Apart from macrophage-secreted profibrotic cytokines, such as TGF-β, evidence for a direct contribution of macrophages to kidney fibrosis is lacking. However, under inflammatory conditions, Wnt ligands are derived mainly from macrophages and Wnt signaling is central in the network of multiple profibrotic pathways. Largely underinvestigated are the direct contribution of macrophages to profibrotic signaling pathways, macrophage phenotypic heterogeneity and functional diversity in relation to kidney fibrosis, and on their cross-talk with other cells in profibrotic signaling networks that cause fibrosis. Here we aim to provide an overview on the roles of macrophage phenotypic and functional diversity in their contribution to pro-fibrotic signaling pathways, and on the therapeutic potential of targeting macrophages for the treatment of kidney fibrosis.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xueyang Zou ◽  
Yi Zhang ◽  
Xiaoya Wang ◽  
Rongchao Zhang ◽  
Wei Yang

The increasing number of patients with infertility is recognized as an emerging problem worldwide. However, little is known about the cause of infertility. At present, it is believed that infertility may be related to genetic or abnormal immune responses. It has long been indicated that autoimmune regulator (AIRE), a transcription factor, participates in immune tolerance by regulating the expression of thousands of promiscuous tissue-specific antigens in medullary thymic epithelial cells (mTECs), which play a pivotal role in preventing autoimmune diseases. AIRE is also expressed in germ cell progenitors. Importantly, the deletion of AIRE leads to severe oophoritis and age-dependent depletion of follicular reserves and causes altered embryonic development in female mice. AIRE-deficient male mice exhibit altered apoptosis during spermatogenesis and have a significantly decreased breeding capacity. These reports suggest that AIRE deficiency may be responsible for infertility. The causes may be related to the production of autoantibodies against sperm, poor development of germ cells, and abnormal ovarian function, which eventually lead to infertility. Here, we focus on the potential associations of AIRE deficiency with infertility as well as the possible pathogenesis, providing insight into the significance of AIRE in the development of infertility.


2008 ◽  
Vol 205 (4) ◽  
pp. 883-895 ◽  
Author(s):  
Rebecca J. Brownlie ◽  
Kate E. Lawlor ◽  
Heather A. Niederer ◽  
Antony J. Cutler ◽  
Zou Xiang ◽  
...  

FcγRIIb is an inhibitory Fc receptor expressed on B cells and myeloid cells. It is important in controlling responses to infection, and reduced expression or function predisposes to autoimmunity. To determine if increased expression of FcγRIIb can modulate these processes, we created transgenic mice overexpressing FcγRIIb on B cells or macrophages. Overexpression of FcγRIIb on B cells reduced the immunoglobulin G component of T-dependent immune responses, led to early resolution of collagen-induced arthritis (CIA), and reduced spontaneous systemic lupus erythematosus (SLE). In contrast, overexpression on macrophages had no effect on immune responses, CIA, or SLE but increased mortality after Streptococcus pneumoniae infection. These results help define the role of FcγRIIb in immune responses, demonstrate the contrasting roles played by FcγRIIb on B cells and macrophages in the control of infection and autoimmunity, and emphasize the therapeutic potential for modulation of FcγRIIb expression on B cells in inflammatory and autoimmune disease.


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