scholarly journals Role of RIG-I-like receptors in innate immune sensing of Coxsackievirus B3 and encephalomyocarditis virus in murine macrophages and fibroblasts

2018 ◽  
Author(s):  
Esther Francisco ◽  
Mehul Suthar ◽  
Michael Gale ◽  
Amy B. Rosenfeld ◽  
Vincent R. Racaniello
Keyword(s):  
Immune Response ◽  
Innate Immune Response ◽  
Coxsackievirus B3 ◽  
Innate Immune ◽  
Encephalomyocarditis Virus ◽  
Type I ◽  
Type I Ifn ◽  
Cell Type ◽  
Murine Macrophages ◽  
Picornavirus Infection

AbstractViral infections are sensed by pattern recognition receptors that trigger an innate immune response through the expression of interferons (IFNs) and other cytokines. Most RNA viruses are sensed by the RIG-I like receptors (RLR)s. The contributions of these receptors to sensing viruses of thePicornaviridaefamily were investigated. Encephalomyocarditis virus (EMCV) and Coxsackievirus B3 (CVB3), picornaviruses of theCardiovirusandEnterovirusgenera, are detected by both MDA5 and RIG-I in bone marrow derived macrophages. In macrophages from wild type mice, type I IFN is produced early after infection; IFNβ synthesis is reduced in the absence of each sensor, while IFNα production is reduced in the absence of MDA5. EMCV and CVB3 do not replicate in murine macrophages, and their detection is different in murine embryonic fibroblasts (MEFs), in which the viruses replicate to high titers. In MEFs RIG-I was essential for the expression of type I IFNs but contributes to increased yields of CVB3, while MDA5 inhibited CVB3 replication but in an IFN independent manner. These observations demonstrate that innate sensing of similar viruses by RLRs depends upon the cell type.ImportanceEnteroviruses such as Coxsackieviruses are the most common human respiratory pathogens. The host’s innate immune response, in particular that modulated by the production of type I and III interferons, is thought to restrict picornavirus infection. Two cytoplasmic proteins, MDA5 and RIG-I, are critical for initiating the early innate immune response against these viruses. Mutations within MDA5 encoding gene have been associated with the development of severe enterovirus associated respiratory illnesses in healthy children. To further understand how the innate immune response dependent upon MDA5 and Rig-I is initiated during picornavirus infection, macrophages from mice lacking MDA5 or RIG-I were infected with Coxsackievirus B3 (CVB3) and a related animal virus. RIG-I is essential for type I IFN production during CVB3 infection; when MDA5 is present, viral titers are reduced by an IFN-independent pathway. These observations demonstrate that innate sensing of viruses by MDA5 and RIG-I depends upon the cell type.

scholarly journals miR-26a Inhibits Feline Herpesvirus 1 Replication by Targeting SOCS5 and Promoting Type I Interferon Signaling

Viruses ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 2 ◽  
Author(s):  
Jikai Zhang ◽  
Zhijie Li ◽  
Jiapei Huang ◽  
Hang Yin ◽  
Jin Tian ◽  
...  
Keyword(s):  
Immune Response ◽  
Viral Infection ◽  
Innate Immune Response ◽  
Antiviral Response ◽  
Innate Immune ◽  
Host Cells ◽  
Type I ◽  
Type I Ifn ◽  
Feline Herpesvirus ◽  
Herpesvirus 1

In response to viral infection, host cells activate various antiviral responses to inhibit virus replication. While feline herpesvirus 1 (FHV-1) manipulates the host early innate immune response in many different ways, the host could activate the antiviral response to counteract it through some unknown mechanisms. MicroRNAs (miRNAs) which serve as a class of regulatory factors in the host, participate in the regulation of the host innate immune response against virus infection. In this study, we found that the expression levels of miR-26a were significantly upregulated upon FHV-1 infection. Furthermore, FHV-1 infection induced the expression of miR-26a via a cGAS-dependent pathway, and knockdown of cellular cGAS significantly blocked the expression of miR-26a induced by poly (dA:dT) or FHV-1 infection. Next, we investigated the biological function of miR-26a during viral infection. miR-26a was able to increase the phosphorylation of STAT1 and promote type I IFN signaling, thus inhibiting viral replication. The mechanism study showed that miR-26a directly targeted host SOCS5. Knockdown of SOCS5 increased the phosphorylation of STAT1 and enhanced the type I IFN-mediated antiviral response, and overexpression of suppressor of the cytokine signalling 5 (SOCS5) decreased the phosphorylation of STAT1 and inhibited the type I IFN-mediated antiviral response. Meanwhile, with the knockdown of SOCS5, the upregulated expression of phosphorylated STAT1 and the anti-virus effect induced by miR-26a were significantly inhibited. Taken together, our data demonstrated a new strategy of host miRNAs against FHV-1 infection by enhancing IFN antiviral signaling.

scholarly journals Innate Immune Response to Adenoviral Vectors Is Mediated by both Toll-Like Receptor-Dependent and -Independent Pathways

2007 ◽  
Vol 81 (7) ◽  
pp. 3170-3180 ◽  
Author(s):  
Jiangao Zhu ◽  
Xiaopei Huang ◽  
Yiping Yang
Keyword(s):  
Gene Therapy ◽  
Immune Response ◽  
Immune Responses ◽  
Innate Immune Response ◽  
Adenoviral Vectors ◽  
Innate Immune ◽  
Type I ◽  
Type I Ifn ◽  
Adaptive Immune ◽  
Type I Ifns

ABSTRACT Recombinant adenoviral vectors have been widely used for gene therapy applications and as vaccine vehicles for treating infectious diseases such as human immunodeficiency virus disease. The innate immune response to adenoviruses represents the most significant hurdle in clinical application of adenoviral vectors for gene therapy, but it is an attractive feature for vaccine development. How adenovirus activates innate immunity remains largely unknown. Here we showed that adenovirus elicited innate immune response through the induction of high levels of type I interferons (IFNs) by both plasmacytoid dendritic cells (pDCs) and non-pDCs such as conventional DCs and macrophages. The innate immune recognition of adenovirus by pDCs was mediated by Toll-like receptor 9 (TLR9) and was dependent on MyD88, whereas that by non-pDCs was TLR independent through cytosolic sensing of adenoviral DNA. Furthermore, type I IFNs were pivotal in innate and adaptive immune responses to adenovirus in vivo, and type I IFN blockade diminished immune responses, resulting in more stable transgene expression and reduction of inflammation. These findings indicate that adenovirus activates innate immunity by its DNA through TLR-dependent and -independent pathways in a cell type-specific fashion, and they highlight a critical role for type I IFNs in innate and adaptive immune responses to adenoviral vectors. Our results that suggest strategies to interfere with type I IFN pathway may improve the outcome of adenovirus-mediated gene therapy, whereas approaches to activate the type I IFN pathway may enhance vaccine potency.

scholarly journals Corticosteroids and cellulose purification improve respectively the in vivo translation and vaccination efficacy of self-amplifying mRNAs

2020 ◽  
Author(s):  
Zifu Zhong ◽  
Séan Mc Cafferty ◽  
Lisa Opsomer ◽  
Haixiu Wang ◽  
Hanne Huysmans ◽  
...  
Keyword(s):  
Immune Response ◽  
Innate Immune Response ◽  
Biomedical Applications ◽  
Innate Immune ◽  
Type I ◽  
Type I Ifn ◽  
Therapeutic Platform ◽  
By Products

AbstractSynthetic mRNAs are an appealing therapeutic platform with multiple biomedical applications ranging from protein replacement therapy to vaccination. In comparison to conventional mRNA, synthetic self-amplifying mRNAs (sa-mRNAs) are gaining increased interest due to their higher and longer-lasting expression. However, sa-mRNAs also elicit an innate immune response, which may complicate the clinical translation of this platform. Approaches to reduce the innate immunity of sa-mRNAs have not been studied in detail. In this work we investigated the effect of several innate immune inhibitors and a novel cellulose-based mRNA purification approach on the type I interferon (IFN) response, translation and vaccination efficacy of our formerly developed sa-mRNA vaccine against Zika virus. Among the investigated inhibitors, we found that topical application of clobetasol at the sa-mRNA injection site was the most efficient in suppressing the type I IFN response and increasing the translation of sa-mRNA. However, clobetasol prevented the formation of antibodies against sa-mRNA encoded antigens and should therefore be avoided in a vaccination context. Residual dsRNA by-products of the in vitro transcription reaction are known inducers of immediate type I IFN responses. We additionally demonstrate drastic reduction of these dsRNA by-products upon cellulose-based purification, consequently reducing the innate immune response and improving sa-mRNA vaccination efficacy.

scholarly journals Type I IFN innate immune response to adenovirus-mediated IFN-γ gene transfer contributes to the regression of cutaneous lymphomas

2007 ◽  
Vol 117 (10) ◽  
pp. 2834-2846 ◽  
Author(s):  
Mirjana Urosevic ◽  
Kazuyasu Fujii ◽  
Bastien Calmels ◽  
Elisabeth Laine ◽  
Nikita Kobert ◽  
...  
Keyword(s):  
Immune Response ◽  
Gene Transfer ◽  
Innate Immune Response ◽  
Innate Immune ◽  
Type I ◽  
Type I Ifn ◽  
Cutaneous Lymphomas ◽  
Ifn Γ

scholarly journals RIG-I-Like Receptor-Mediated Recognition of Viral Genomic RNA of Severe Acute Respiratory Syndrome Coronavirus-2 and Viral Escape From the Host Innate Immune Responses

2021 ◽  
Vol 12 ◽  
Author(s):  
Takahisa Kouwaki ◽  
Tasuku Nishimura ◽  
Guanming Wang ◽  
Hiroyuki Oshiumi
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Innate Immune Response ◽  
Cytokine Expression ◽  
Innate Immune ◽  
Viral Escape ◽  
Type I ◽  
Type I Ifn ◽  
Innate Immune Responses ◽  
Viral Genomic Rna

RIG-I-like receptors (RLR), RIG-I and MDA5, are cytoplasmic viral RNA sensors that recognize viral double-stranded RNAs and trigger signals to induce antiviral responses, including type I interferon production. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) caused the coronavirus disease 2019 pandemic. However, the RLR role in innate immune response to SARS-CoV-2 has not been fully elucidated. Here, we studied the roles of RLR in cytokine expression responding to SARS-CoV-2 and found that not only MDA5 but also RIG-I are involved in innate immune responses in some types of human cells. Transfection of total RNAs extracted from SARS-CoV-2-infected cells into epithelial cells induced IFN-β, IP-10, and Ccl5 mRNA expression. The cytokine expression was reduced by knockout of either RIG-I or MDA5, suggesting that both proteins are required for appropriate innate immune response to SARS-CoV-2. Two viral genomic RNA regions strongly induced type I IFN expression, and a 200-base fragment of viral RNA preferentially induced type I IFN in a RIG-I-dependent manner. In contrast, SARS-CoV-2 infectious particles hardly induced cytokine expression, suggesting viral escape from the host response. Viral 9b protein inhibited RIG-I and MAVS interaction, and viral 7a protein destabilized the TBK1 protein, leading to attenuated IRF-3 phosphorylation required for type I IFN expression. Our data elucidated the mechanism underlying RLR-mediated response to SARS-CoV-2 infection and viral escape from the host innate immune response.

scholarly journals Lymphocytes are detrimental during the early innate immune response against Listeria monocytogenes

2006 ◽  
Vol 203 (4) ◽  
pp. 933-940 ◽  
Author(s):  
Javier A. Carrero ◽  
Boris Calderon ◽  
Emil R. Unanue
Keyword(s):  
Immune Response ◽  
Listeria Monocytogenes ◽  
Innate Immune Response ◽  
Early Stage ◽  
Bacterial Pathogen ◽  
Interleukin 10 ◽  
Innate Immune ◽  
Type I ◽  
Phagocytic Cells ◽  
Immunodeficient Mice

Mice deficient in lymphocytes are more resistant than normal mice to Listeria monocytogenes infection during the early innate immune response. This paradox remains unresolved: lymphocytes are required for sterilizing immunity, but their presence during the early stage of the infection is not an asset and may even be detrimental. We found that lymphocyte-deficient mice, which showed limited apoptosis in infected organs, were resistant during the first four days of infection but became susceptible when engrafted with lymphocytes. Engraftment with lymphocytes from type I interferon receptor–deficient (IFN-αβR−/−) mice, which had reduced apoptosis, did not confer increased susceptibility to infection, even when the phagocytes were IFN-αβR+/+. The attenuation of innate immunity was due, in part, to the production of the antiinflammatory cytokine interleukin 10 by phagocytic cells after the apoptotic phase of the infection. Thus, immunodeficient mice were more resistant relative to normal mice because the latter went through a stage of lymphocyte apoptosis that was detrimental to the innate immune response. This is an example of a bacterial pathogen creating a cascade of events that leads to a permissive infective niche early during infection.

Type I interferons and the innate immune response—more than just antiviral cytokines

2005 ◽  
Vol 42 (8) ◽  
pp. 869-877 ◽  
Author(s):  
Peter L Smith ◽  
Giovanna Lombardi ◽  
Graham R Foster
Keyword(s):  
Immune Response ◽  
Innate Immune Response ◽  
Innate Immune ◽  
Type I Interferons ◽  
Type I

High content screening and computational prediction reveal viral genes that suppress innate immune response

2021 ◽  
Author(s):  
Tai L Ng ◽  
Erika J Olson ◽  
Tae Yeon Yoo ◽  
H. Sloane Weiss ◽  
Yukiye Koide ◽  
...  
Keyword(s):  
Immune Response ◽  
Innate Immune Response ◽  
Nuclear Transport ◽  
Computational Prediction ◽  
Viral Proteins ◽  
Innate Immune ◽  
Type I ◽  
Viral Genes ◽  
Genes Encoding

Suppression of the host innate immune response is a critical aspect of viral replication. Upon infection, viruses may introduce one or more proteins that inhibit key immune pathways, such as the type I interferon pathway. However, the ability to predict and evaluate viral protein bioactivity on targeted pathways remains challenging and is typically done on a single virus/gene basis. Here, we present a medium-throughput high-content cell-based assay to reveal the immunosuppressive effects of viral proteins. To test the predictive power of our approach, we developed a library of 800 genes encoding known, predicted, and uncharacterized human viral genes. We find that previously known immune suppressors from numerous viral families such as Picornaviridae and Flaviviridae recorded positive responses. These include a number of viral proteases for which we further confirmed that innate immune suppression depends on protease activity. A class of predicted inhibitors encoded by Rhabdoviridae viruses was demonstrated to block nuclear transport, and several previously uncharacterized proteins from uncultivated viruses were shown to inhibit nuclear transport of the transcription factors NF-kB and IRF3. We propose that this pathway-based assay, together with early sequencing, gene synthesis, and viral infection studies, could partly serve as the basis for rapid in vitro characterization of novel viral proteins.

scholarly journals Longitudinal single-cell immune profiling revealed distinct innate immune response in asymptomatic COVID-19 patients

2020 ◽  
Author(s):  
Xiang-Na Zhao ◽  
Yue You ◽  
Guo-Lin Wang ◽  
Hui-Xia Gao ◽  
Xiao-Ming Cui ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Single Cell ◽  
Innate Immune Response ◽  
Clonal Expansion ◽  
Innate Immune ◽  
Type I ◽  
Severe Condition ◽  
Asymptomatic Patients

SUMMARYRecent studies have characterized the single-cell immune landscape of host immune response of coronavirus disease 2019 (COVID-19), specifically focus on the severe condition. However, the immune response in mild or even asymptomatic patients remains unclear. Here, we performed longitudinal single-cell transcriptome sequencing and T cell/B cell receptor sequencing on 3 healthy donors and 10 COVID-19 patients with asymptomatic, moderate, and severe conditions. We found asymptomatic patients displayed distinct innate immune responses, including increased CD56briCD16− NK subset, which was nearly missing in severe condition and enrichment of a new Th2-like cell type/state expressing a ciliated cell marker. Unlike that in moderate condition, asymptomatic patients lacked clonal expansion of effector CD8+ T cells but had a robust effector CD4+ T cell clonal expansion, coincide with previously detected SARS-CoV-2-reactive CD4+ T cells in unexposed individuals. Moreover, NK and effector T cells in asymptomatic patients have upregulated cytokine related genes, such as IFNG and XCL2. Our data suggest early innate immune response and type I immunity may contribute to the asymptomatic phenotype in COVID-19 disease, which could in turn deepen our understanding of severe COVID-19 and guide early prediction and therapeutics.

The C-terminal domain of Salmonid Alphavirus nonstructural protein 2 (nsP2) is essential and sufficient to block RIG-I pathway induction and interferon-mediated antiviral response.

2021 ◽  
Author(s):  
Raphaël Jami ◽  
Emilie Mérour ◽  
Julie Bernard ◽  
Annie Lamoureux ◽  
Jean K. Millet ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Innate Immune Response ◽  
Nuclear Localization ◽  
Innate Immune ◽  
Type I ◽  
Annual Growth Rate ◽  
Structural Protein ◽  
Terminal Domain ◽  
Nuclear Localization Sequences

Salmonid alphavirus (SAV) is an atypical alphavirus, which has a considerable impact on salmon and trout farms. Unlike other alphaviruses such as the chikungunya virus, SAV is transmitted without an arthropod vector, and does not cause cell shut-off during infection. The mechanisms by which SAV escapes the host immune system remain unknown. By studying the role of SAV proteins on the RIG-I signaling cascade, the first line of defense of the immune system during infection, we demonstrated that non-structural protein 2 (nsP2) effectively blocks the induction of type I interferon (IFN). This inhibition, independent of the protease activity carried by nsP2, occurs downstream of IRF3 which is the transcription factor allowing the activation of the IFN promoter and its expression. The inhibitory effect of nsP2 on the RIG-I pathway depends on the localization of nsP2 in the host cell nucleus which is linked to two nuclear localization sequences (NLS) located in its C-terminal part. The C-terminal domain of nsP2 by itself is sufficient and necessary to block IFN induction. Mutation of the NLS of nsP2 is deleterious to the virus. Finally, nsP2 does not interact with IRF3, indicating that its action is possible through a targeted interaction within discrete areas of chromatin, as suggested by its punctate distribution observed in the nucleus. These results therefore demonstrate a major role for nsP2 in the control by SAV of the host cell’s innate immune response. Importance The global consumption of fish continues to rise and the future demand cannot be met by capture fisheries alone due to limited stocks of wild fish. Aquaculture is currently the world’s fastest growing food production sector with an annual growth rate of 6-8 %. Recurrent outbreaks of SAV result in significant economic losses with serious environmental consequences on wild stocks. While the clinical and pathological signs of SAV infection are fairly well known, the molecular mechanisms involved are poorly described. In the present study, we focus on the non-structural protein nsP2 and characterize a specific domain containing nuclear localization sequences that are critical for the inhibition of the host innate immune response mediated by the RIG-I pathway.

Sign in / Sign up

Export Citation Format

Share Document