scholarly journals YTHDF1 drives intestinal immune response against bacterial infection

2020 ◽  
Author(s):  
Xin Zong ◽  
Xiao Xiao ◽  
Bin Shen ◽  
Qin Jiang ◽  
Hong Wang ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Bacterial Infection ◽  
Pathogenic Bacteria ◽  
Stop Codon ◽  
Tumor Necrosis Factor Receptor ◽  
Underlying Mechanism ◽  
Innate Immune Responses ◽  
Key Driver ◽  
Unique Mechanism

AbstractInvasion of pathogenic bacteria is a serious threat to intestinal health. Recent emerging evidence has demonstrated that N6-methyladenosine (m6A) is closely associated with innate immunity; however, the underlying mechanism remains unclear. Herein, we aim to explore the function and mechanism of m6A modification in the regulation of innate immune responses against bacterial pathogens in the intestine. Ribo-seq and m6A-seq data have demonstrated that YTHDF1, an m6A reader, directs the translation of tumor necrosis factor receptor-associated factor 6 (TRAF6) mRNA to regulate immune responses via modulation of m6A methylation near stop codon. Furthermore, we have identified a unique mechanism that the interaction between YTHDF1 and the host factor DDX60 are critical in regulating intestinal immune response against bacterial infection by recognizing TRAF6 target transcripts. Additionally, our results provide novel insights as to why YTHDF1 could recognize its unique targets using the same domain as other YTHDF proteins. This work identifies YTHDF1 as a key driver of intestinal immune responses and provides an avenue for development of novel strategies to modulate intestinal immune response against bacterial infection.

scholarly journals Therapeutic Approaches for COVID-19 Based on the Dynamics of Interferon-mediated Immune Responses

2020 ◽  
Author(s):  
Farbod Shahabi nezhad ◽  
Pouria Mosaddeghi ◽  
Manica Negahdaripour ◽  
Zahra Dehghani ◽  
Mitra Farahmandnejad ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Immune Responses ◽  
The Elderly ◽  
Underlying Mechanism ◽  
Innate Immune ◽  
Response Threshold ◽  
Innate Immune Responses ◽  
Optimum Approach ◽  
Novel Virus

As the outbreak of COVID-19 has accelerated, an urgent need for finding strategies to combat the virus is growing. Thus, gaining more knowledge on the pathogenicity mechanism of SARS-CoV-2, the causing agent of COVID-19, and its interaction with the immune system is of utmost importance. Although this novel virus is not well known yet, its structural and genetic similarity with SARS-CoV as well as the comparable pattern of age-mortality relations suggest that the previous findings on SARS can be applicable for COVID-19. Therefore, a systems biology study was conducted to investigate the underlying mechanism for the differences in the age-specific mortality of SARS and the most important signaling pathways activated by the virus. The results were then validated through a literature review on COVID-19 and the other closely related viruses, SARS and MERS. Interferons have shown to possess a crucial role in the defense against coronavirus diseases. The virus can impede the interferon induction in humans. Moreover, STAT1, a key protein in the interferon mediated immune response, is antagonized by the virus. This could explain the increased response threshold of immune cells to IFNs during CoV infections. A vivid correlation between the innate immune response threshold and the fatality rates in COVID-19 can be found. Differences in the dynamics of the interferons-related innate immune responses in children, adults and elderly may explain the reported fatality rates. The increased mortality rates in the elderly can be explained by the higher threshold of interferon-mediated immune responses. Earlier induction of interferons in children and their less developed immune system could be the reason behind their zero or near to zero fatality rate. Administration of interferon-inducing agents, such as Poly (ICLC), could reduce the mortality of SARS at the very early stages of the disease. Adding interferon-γ to an interferon-I, as a synergistic combination therapy, might maximize the benefits.At the later stages of the disease, however, the balance of the immune reactions would be disrupted and the responses would shift toward immnopathogenic over-reactions and probably cytokine storm. Moderating the activity of the immune system and supportive care in such conditions might be the optimum approach.

Oral Immune Activation by Disgust and Disease-Related Pictures

2015 ◽  
Vol 29 (3) ◽  
pp. 119-129 ◽  
Author(s):  
Richard J. Stevenson ◽  
Deborah Hodgson ◽  
Megan J. Oaten ◽  
Luba Sominsky ◽  
Mehmet Mahmut ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Innate Immune Response ◽  
Negative Control ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Immune Markers ◽  
Before And After ◽  
Secondary Analyses ◽  
Image Set

Abstract. Both disgust and disease-related images appear able to induce an innate immune response but it is unclear whether these effects are independent or rely upon a common shared factor (e.g., disgust or disease-related cognitions). In this study we directly compared these two inductions using specifically generated sets of images. One set was disease-related but evoked little disgust, while the other set was disgust evoking but with less disease-relatedness. These two image sets were then compared to a third set, a negative control condition. Using a wholly within-subject design, participants viewed one image set per week, and provided saliva samples, before and after each viewing occasion, which were later analyzed for innate immune markers. We found that both the disease related and disgust images, relative to the negative control images, were not able to generate an innate immune response. However, secondary analyses revealed innate immune responses in participants with greater propensity to feel disgust following exposure to disease-related and disgusting images. These findings suggest that disgust images relatively free of disease-related themes, and disease-related images relatively free of disgust may be suboptimal cues for generating an innate immune response. Not only may this explain why disgust propensity mediates these effects, it may also imply a common pathway.

scholarly journals Innate cell profiles during the acute and convalescent phase of SARS-CoV-2 infection in children

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Melanie R. Neeland ◽  
Samantha Bannister ◽  
Vanessa Clifford ◽  
Kate Dohle ◽  
Kim Mulholland ◽  
...  
Keyword(s):  
Immune Response ◽  
Dendritic Cells ◽  
Immune Responses ◽  
Acute Phase ◽  
Innate Immune ◽  
Low Density ◽  
Innate Immune Responses ◽  
Immunological Mechanisms ◽  
Activated Neutrophils ◽  
Classical Monocytes

AbstractChildren have mild severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) confirmed disease (COVID-19) compared to adults and the immunological mechanisms underlying this difference remain unclear. Here, we report acute and convalescent innate immune responses in 48 children and 70 adults infected with, or exposed to, SARS-CoV-2. We find clinically mild SARS-CoV-2 infection in children is characterised by reduced circulating subsets of monocytes (classical, intermediate, non-classical), dendritic cells and natural killer cells during the acute phase. In contrast, SARS-CoV-2-infected adults show reduced proportions of non-classical monocytes only. We also observe increased proportions of CD63+ activated neutrophils during the acute phase to SARS-CoV-2 in infected children. Children and adults exposed to SARS-CoV-2 but negative on PCR testing display increased proportions of low-density neutrophils that we observe up to 7 weeks post exposure. This study characterises the innate immune response during SARS-CoV-2 infection and household exposure in children.

scholarly journals An In Vitro Assessment of Immunostimulatory Responses to Ten Model Innate Immune Response Modulating Impurities (IIRMIs) and Peptide Drug Product, Teriparatide

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7461
Author(s):  
Claire K. Holley ◽  
Edward Cedrone ◽  
Duncan Donohue ◽  
Barry W. Neun ◽  
Daniela Verthelyi ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Innate Immune Response ◽  
Innate Immune ◽  
Cytokine Secretion ◽  
Poly I:C ◽  
In Vitro Assays ◽  
Innate Immune Responses ◽  
Vitro Assay

Understanding, predicting, and minimizing the immunogenicity of peptide-based therapeutics are of paramount importance for ensuring the safety and efficacy of these products. The so-called anti-drug antibodies (ADA) may have various clinical consequences, including but not limited to the alteration in the product’s distribution, biological activity, and clearance profiles. The immunogenicity of biotherapeutics can be influenced by immunostimulation triggered by the presence of innate immune response modulating impurities (IIRMIs) inadvertently introduced during the manufacturing process. Herein, we evaluate the applicability of several in vitro assays (i.e., complement activation, leukocyte proliferation, and cytokine secretion) for the screening of innate immune responses induced by ten common IIRMIs (Bacillus subtilis flagellin, FSL-1, zymosan, ODN2006, poly(I:C) HMW, poly(I:C) LMW, CLO75, MDP, ODN2216, and Escherichia coli O111:B4 LPS), and a model biotherapeutic Forteo™ (teriparatide). Our study identifies cytokine secretion from healthy human donor peripheral blood mononuclear cells (PBMC) as a sensitive method for the in vitro monitoring of innate immune responses to individual IIRMIs and teriparatide (TP). We identify signature cytokines, evaluate both broad and narrow multiplex cytokine panels, and discuss how the assay logistics influence the performance of this in vitro assay.

scholarly journals The Sp1-Responsive microRNA-15b Negatively Regulates Rhabdovirus-Triggered Innate Immune Responses in Lower Vertebrates by Targeting TBK1

2021 ◽  
Vol 11 ◽  
Author(s):  
Renjie Chang ◽  
Qing Chu ◽  
Weiwei Zheng ◽  
Lei Zhang ◽  
Tianjun Xu
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Innate Immune ◽  
Infection Model ◽  
Regulation Mechanism ◽  
Type I ◽  
Innate Immune Responses ◽  
Positive Role ◽  
Siniperca Chuatsi ◽  
Antiviral Immune Response

As is known to all, the production of type I interferon (IFN) plays pivotal roles in host innate antiviral immunity, and its moderate production play a positive role in promoting the activation of host innate antiviral immune response. However, the virus will establish a persistent infection model by interfering with the production of IFN, thereby evading the organism inherent antiviral immune response. Therefore, it is of great necessity to research the underlying regulatory mechanisms of type I IFN appropriate production under viral invasion. In this study, we report that a Sp1–responsive miR-15b plays a negative role in siniperca chuatsi rhabdovirus (SCRV)-triggered antiviral response in teleost fish. We found that SCRV could dramatically upregulate miiuy croaker miR-15b expression. Enhanced miR-15b could negatively regulate SCRV-triggered antiviral genes and inflammatory cytokines production by targeting TANK-binding kinase 1 (TBK1), thereby accelerating viral replication. Importantly, we found that miR-15b feedback regulates antiviral innate immune response through NF-κB and IRF3 signaling pathways. These findings highlight that miR-15b plays a crucial role in regulating virus–host interactions, which outlines a new regulation mechanism of fish’s innate immune responses.

Galectin-8 in the onset of the immune response and inflammation

Glycobiology ◽  
2019 ◽  
Vol 30 (3) ◽  
pp. 134-142 ◽  
Author(s):  
María V Tribulatti ◽  
Julieta Carabelli ◽  
Cecilia A Prato ◽  
Oscar Campetella
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Innate Immune ◽  
High Expression ◽  
Innate Immune Responses ◽  
Inflammatory Disorders ◽  
Anti Inflammatory ◽  
Potential Use

Abstract Galectins (Gals), a family of mammalian lectins, have emerged as key regulators of the immune response, being implicated in several physiologic and pathologic conditions. Lately, there is increasing data regarding the participation of Galectin-8 (Gal-8) in both the adaptive and innate immune responses, as well as its high expression in inflammatory disorders. Here, we focus on the pro- and anti-inflammatory properties of Gal-8 and discuss the potential use of this lectin in order to shape the immune response, according to the context.

scholarly journals The role of type 1 interferons in Gram-negative bacteria-induced coagulation

Blood ◽  
2020 ◽  
Author(s):  
Xinyu Yang ◽  
Xiaoye Cheng ◽  
Yiting Tang ◽  
Xianhui Qiu ◽  
Zhongtai Wang ◽  
...  
Keyword(s):  
Immune Responses ◽  
Bacterial Infection ◽  
Innate Immune ◽  
Coagulation Cascade ◽  
Outer Cell ◽  
Gram Negative Bacteria ◽  
Innate Immune Responses ◽  
Gram Negative ◽  
Type 1 Interferons

Bacterial infection not only stimulates innate immune responses but also activates the coagulation cascades. Over-activation of the coagulation system in bacterial sepsis leads to disseminated intravascular coagulation (DIC), a life-threatening condition. However, the mechanisms by which bacterial infection activates the coagulation cascade are not fully understood. Here we show that type 1 interferons (IFNs), widely expressed family of cytokines that orchestrate innate antiviral and antibacterial immunity, mediate bacterial infection-induced DIC through amplifying the release of high mobility box group box 1 (HMGB1) into the blood stream. Inhibition of the expression of type 1 IFNs, disruption of their receptor IFN-α/βR or downstream effector (e.g., HMGB1) uniformly decreased Gram-negative bacteria-induced DIC. Mechanistically, extracellular HMGB1 markedly increased the pro-coagulant activity of tissue factor (TF) by promoting the externalization of phosphatidylserine (PS) to the outer cell surface, where PS assembles a complex of cofactor-proteases of the coagulation cascades. These findings not only provide novel insights into the link between innate immune responses and coagulation, but also open a new avenue for developing novel therapeutic strategies to prevent DIC in sepsis.

scholarly journals Innate Immune Responses of Bat and Human Cells to Filoviruses: Commonalities and Distinctions

2017 ◽  
Vol 91 (8) ◽  
Author(s):  
Ivan V. Kuzmin ◽  
Toni M. Schwarz ◽  
Philipp A. Ilinykh ◽  
Ingo Jordan ◽  
Thomas G. Ksiazek ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Innate Immune Response ◽  
Antiviral Effect ◽  
Human Cells ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Symptomatic Disease ◽  
Ifn Γ

ABSTRACT Marburg (MARV) and Ebola (EBOV) viruses are zoonotic pathogens that cause severe hemorrhagic fever in humans. The natural reservoir of MARV is the Egyptian rousette bat (Rousettus aegyptiacus); that of EBOV is unknown but believed to be another bat species. The Egyptian rousette develops subclinical productive infection with MARV but is refractory to EBOV. Interaction of filoviruses with hosts is greatly affected by the viral interferon (IFN)-inhibiting domains (IID). Our study was aimed at characterization of innate immune responses to filoviruses and the role of filovirus IID in bat and human cells. The study demonstrated that EBOV and MARV replicate to similar levels in all tested cell lines, indicating that permissiveness for EBOV at cell and organism levels do not necessarily correlate. Filoviruses, particularly MARV, induced a potent innate immune response in rousette cells, which was generally stronger than that in human cells. Both EBOV VP35 and VP24 IID were found to suppress the innate immune response in rousette cells, but only VP35 IID appeared to promote virus replication. Along with IFN-α and IFN-β, IFN-γ was demonstrated to control filovirus infection in bat cells but not in human cells, suggesting host species specificity of the antiviral effect. The antiviral effects of bat IFNs appeared not to correlate with induction of IFN-stimulated genes 54 and 56, which were detected in human cells ectopically expressing bat IFN-α and IFN-β. As bat IFN-γ induced the type I IFN pathway, its antiviral effect is likely to be partially induced via cross talk. IMPORTANCE Bats serve as reservoirs for multiple emerging viruses, including filoviruses, henipaviruses, lyssaviruses, and zoonotic coronaviruses. Although there is no evidence for symptomatic disease caused by either Marburg or Ebola viruses in bats, spillover of these viruses into human populations causes deadly outbreaks. The reason for the lack of symptomatic disease in bats infected with filoviruses remains unknown. The outcome of a virus-host interaction depends on the ability of the host immune system to suppress viral replication and the ability of a virus to counteract the host defenses. Our study is a comparative analysis of the host innate immune response to either MARV or EBOV infection in bat and human cells and the role of viral interferon-inhibiting domains in the host innate immune responses. The data are useful for understanding the interactions of filoviruses with natural and accidental hosts and for identification of factors that influence filovirus evolution.

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