scholarly journals Type I Interferon at the Interface of Antiviral Immunity and Immune Regulation: The Curious Case of HIV-1

Scientifica ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-20 ◽  
Author(s):  
Adriano Boasso
Keyword(s):  
Immune Response ◽  
Molecular Mechanisms ◽  
Viral Infections ◽  
Type I Interferon ◽  
Critical Role ◽  
Antiviral Immunity ◽  
Target Cells ◽  
Type I ◽  
Cell Immunity ◽  
Hiv 1

Type I interferon (IFN-I) play a critical role in the innate immune response against viral infections. They actively participate in antiviral immunity by inducing molecular mechanisms of viral restriction and by limiting the spread of the infection, but they also orchestrate the initial phases of the adaptive immune response and influence the quality of T cell immunity. During infection with the human immunodeficiency virus type 1 (HIV-1), the production of and response to IFN-I may be severely altered by the lymphotropic nature of the virus. In this review I consider the different aspects of virus sensing, IFN-I production, signalling, and effects on target cells, with a particular focus on the alterations observed following HIV-1 infection.

scholarly journals Crosstalk between Autophagy and Type I Interferon Responses in Innate Antiviral Immunity

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 132 ◽  
Author(s):  
Yu Tian ◽  
Ming-Li Wang ◽  
Jun Zhao
Keyword(s):  
Innate Immunity ◽  
Immune System ◽  
Molecular Mechanisms ◽  
Viral Infections ◽  
Type I Interferon ◽  
Antiviral Immunity ◽  
Type I ◽  
Viral Components ◽  
Interferon Responses ◽  
Innate Antiviral Immunity

Autophagy exhibits dual effects during viral infections, promoting the clearance of viral components and activating the immune system to produce antiviral cytokines. However, some viruses impair immune defenses by collaborating with autophagy. Mounting evidence suggests that the interaction between autophagy and innate immunity is critical to understanding the contradictory roles of autophagy. Type I interferon (IFN-I) is a crucial antiviral factor, and studies have indicated that autophagy affects IFN-I responses by regulating IFN-I and its receptors expression. Similarly, IFN-I and interferon-stimulated gene (ISG) products can harness autophagy to regulate antiviral immunity. Crosstalk between autophagy and IFN-I responses could be a vital aspect of the molecular mechanisms involving autophagy in innate antiviral immunity. This review briefly summarizes the approaches by which autophagy regulates antiviral IFN-I responses and highlights the recent advances on the mechanisms by which IFN-I and ISG products employ autophagy against viruses.

scholarly journals Complexities of Type I Interferon Biology: Lessons from LCMV

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 172 ◽  
Author(s):  
Tamara Suprunenko ◽  
Markus Hofer
Keyword(s):  
Molecular Mechanisms ◽  
Viral Infections ◽  
Type I Interferon ◽  
Malignant Tumors ◽  
Antiviral Immunity ◽  
Lymphocytic Choriomeningitis ◽  
Type I Interferons ◽  
Host Responses ◽  
Type I ◽  
Novel Treatments

Over the past decades, infection of mice with lymphocytic choriomeningitis virus (LCMV) has provided an invaluable insight into our understanding of immune responses to viruses. In particular, this model has clarified the central roles that type I interferons play in initiating and regulating host responses. The use of different strains of LCMV and routes of infection has allowed us to understand how type I interferons are critical in controlling virus replication and fostering effective antiviral immunity, but also how they promote virus persistence and functional exhaustion of the immune response. Accordingly, these discoveries have formed the foundation for the development of novel treatments for acute and chronic viral infections and even extend into the management of malignant tumors. Here we review the fundamental insights into type I interferon biology gained using LCMV as a model and how the diversity of LCMV strains, dose, and route of administration have been used to dissect the molecular mechanisms underpinning acute versus persistent infection. We also identify gaps in the knowledge regarding LCMV regulation of antiviral immunity. Due to its unique properties, LCMV will continue to remain a vital part of the immunologists’ toolbox.

scholarly journals How fragile we are. Influence of STimulator of INterferon Genes, STING, variants on pathogen recognition and immune response efficiency

2021 ◽  
Author(s):  
Jeremy Morere ◽  
Cecilia Hognon ◽  
Tom Miclot ◽  
Tao Jiang ◽  
Elise Dumont ◽  
...  
Keyword(s):  
Immune Response ◽  
Molecular Mechanisms ◽  
Viral Infections ◽  
Inflammatory Diseases ◽  
Dynamical Behavior ◽  
Structural Features ◽  
Type I Interferons ◽  
Machine Learning Techniques ◽  
Type I ◽  
Interaction Patterns

The STimulator of INterferon Genes (STING) protein is a cornerstone of the human immune response. Its activation by cGAMP upon the presence of cytosolic DNA stimulates the production of type I interferons and inflammatory cytokines which are crucial for protecting cells from infections. STING signaling pathway can also influence both tumor-suppressive and tumor-promoting mechanisms, rendering it an appealing target for drug design. In the human population, several STING variants exist and exhibit dramatic differences in their activity, impacting the efficiency of the host defense against infections. Understanding the differential molecular mechanisms exhibited by these variants is of utmost importance notably towards personalized medicine treatments against diseases such as viral infections (COVID-19, Dengue...), cancers, or auto-inflammatory diseases. Owing to micro-seconds scale molecular modeling simulations and post-processing by contacts analysis and Machine Learning techniques, we reveal the dynamical behavior of four STING variants (wild type, G230A, R293Q, and G230A-R293Q) and we rationalize the variability of efficiency observed experimentally. Our results show that the decrease of STING activity is linked to a stiffening of key-structural features of the binding cavity, together with changes of the interaction patterns within the protein.

scholarly journals Vpu-Deficient HIV Strains Stimulate Innate Immune Signaling Responses in Target Cells

2012 ◽  
Vol 86 (16) ◽  
pp. 8499-8506 ◽  
Author(s):  
Brian P. Doehle ◽  
Kristina Chang ◽  
Lamar Fleming ◽  
John McNevin ◽  
Florian Hladik ◽  
...  
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Host Cell ◽  
Innate Immune Response ◽  
Innate Immune ◽  
Target Cells ◽  
Major Public Health Problem ◽  
Type I ◽  
Innate Defense ◽  
Hiv 1

Acute virus infection induces a cell-intrinsic innate immune response comprising our first line of immunity to limit virus replication and spread, but viruses have developed strategies to overcome these defenses. HIV-1 is a major public health problem; however, the virus-host interactions that regulate innate immune defenses against HIV-1 are not fully defined. We have recently identified the viral protein Vpu to be a key determinant responsible for HIV-1 targeting and degradation of interferon regulatory factor 3 (IRF3), a central transcription factor driving host cell innate immunity. IRF3 plays a major role in pathogen recognition receptor (PRR) signaling of innate immunity to drive the expression of type I interferon (IFN) and interferon-stimulated genes (ISGs), including a variety of HIV restriction factors, that serve to limit viral replication directly and/or program adaptive immunity. Here we interrogate the cellular responses to target cell infection with Vpu-deficient HIV-1 strains. Remarkably, in the absence of Vpu, HIV-1 triggers a potent intracellular innate immune response that suppresses infection. Thus, HIV-1 can be recognized by PRRs within the host cell to trigger an innate immune response, and this response is unmasked only in the absence of Vpu. Vpu modulation of IRF3 therefore prevents virus induction of specific innate defense programs that could otherwise limit infection. These observations show that HIV-1 can indeed be recognized as a pathogen in infected cells and provide a novel and effective platform for defining the native innate immune programs of target cells of HIV-1 infection.

scholarly journals Interferon-α subtype treatment induces the repression of SRSF1 in HIV-1 target cells and affects HIV-1 post integration steps

2021 ◽  
Author(s):  
Helene Sertznig ◽  
Fabian Roesmann ◽  
Barbara Bleekmann ◽  
Carina Elsner ◽  
Mario L Santiago ◽  
...  
Keyword(s):  
Particle Production ◽  
Viral Infections ◽  
Chronic Phase ◽  
Immune Defense ◽  
Interferon Α ◽  
Target Cells ◽  
Type I ◽  
Mrna Levels ◽  
Expression Levels ◽  
Hiv 1

Efficient replication of HIV-1 depends on balanced levels of host cell components, including cellular splicing factors. Type I interferons (IFN-I), playing a crucial role in the innate immune defense against viral infections, are well known to induce the transcription of IFN-stimulated genes (ISGs) including potent host restriction factors. Not so well known is, that IFN-repressed genes (IRepGs) also affect viral infections by downregulating host dependency factors that are essential for viral replication. So far, knowledge about IRepGs involved in HIV-1 infection is very limited. Here, we demonstrate that expression levels of the serine/arginine-rich splicing factor 1 (SRSF1) were repressed upon treatment with IFNα subtypes in HIV-1 susceptible cell lines as well as primary cells. Furthermore, we could demonstrate in two independent patient cohorts that HIV-1 infection and the concomitant inflammation during the acute and chronic phase, resulted in the strong induction of ISGs, but at the same time significantly repressed SRSF1. 4sU-labeling of newly transcribed mRNAs revealed that IFN-mediated repression of SRSF1 originated from a transcriptional shutdown. Experimental downregulation as well as overexpression of SRSF1 expression levels resulted in crucial changes in HIV-1 LTR-transcription, alternative splice site usage and virus production. While lower SRSF1 levels resulted in low vif mRNA levels and thus severely reduced viral infectivity, higher levels of SRSF1 impaired LTR-Tat-activity and HIV-1 particle production. Our data highlight the so far undescribed role of SRSF1 acting as an IFN-repressed cellular dependency factor decisively regulating HIV-1 post integration steps.

scholarly journals Alteration of type I interferon response is associated with subclinical atherosclerosis in virologically suppressed HIV‐1‐infected male patients

2021 ◽  
Author(s):  
Letizia Santinelli ◽  
Gabriella De Girolamo ◽  
Cristian Borrazzo ◽  
Paolo Vassalini ◽  
Claudia Pinacchio ◽  
...  
Keyword(s):  
Type I Interferon ◽  
Subclinical Atherosclerosis ◽  
Interferon Response ◽  
Type I ◽  
Infected Male ◽  
Male Patients ◽  
Hiv 1

scholarly journals Activation of Stimulator of Interferon Genes (STING) and Sjögren Syndrome

2018 ◽  
Vol 97 (8) ◽  
pp. 893-900 ◽  
Author(s):  
J. Papinska ◽  
H. Bagavant ◽  
G.B. Gmyrek ◽  
M. Sroka ◽  
S. Tummala ◽  
...  
Keyword(s):  
Gene Expression ◽  
Viral Infections ◽  
Critical Role ◽  
Autoimmune Disorder ◽  
Sjögren Syndrome ◽  
Lymphoid Cells ◽  
Type I Interferons ◽  
Sjogren Syndrome ◽  
Type I ◽  
Type I Ifns

Sjögren syndrome (SS), a chronic autoimmune disorder causing dry mouth, adversely affects the overall oral health in patients. Activation of innate immune responses and excessive production of type I interferons (IFNs) play a critical role in the pathogenesis of this disorder. Recognition of nucleic acids by cytosolic nucleic acid sensors is a major trigger for the induction of type I IFNs. Upon activation, cytosolic DNA sensors can interact with the stimulator of interferon genes (STING) protein, and activation of STING causes increased expression of type I IFNs. The role of STING activation in SS is not known. In this study, to investigate whether the cytosolic DNA sensing pathway influences SS development, female C57BL/6 mice were injected with a STING agonist, dimethylxanthenone-4-acetic acid (DMXAA). Salivary glands (SGs) were studied for gene expression and inflammatory cell infiltration. SG function was evaluated by measuring pilocarpine-induced salivation. Sera were analyzed for cytokines and autoantibodies. Primary SG cells were used to study the expression and activation of STING. Our data show that systemic DMXAA treatment rapidly induced the expression of Ifnb1, Il6, and Tnfa in the SGs, and these cytokines were also elevated in circulation. In contrast, increased Ifng gene expression was dominantly detected in the SGs. The type I innate lymphoid cells present within the SGs were the major source of IFN-γ, and their numbers increased significantly within 3 d of treatment. STING expression in SGs was mainly observed in ductal and interstitial cells. In primary SG cells, DMXAA activated STING and induced IFN-β production. The DMXAA-treated mice developed autoantibodies, sialoadenitis, and glandular hypofunction. Our study demonstrates that activation of the STING pathway holds the potential to initiate SS. Thus, apart from viral infections, conditions that cause cellular perturbations and accumulation of host DNA within the cytosol should also be considered as possible triggers for SS.

scholarly journals Comparison of Type I Interferon Expression in Adult and Neonatal Mice during Respiratory Viral Infection

10.29007/ltkw ◽  
2019 ◽  
Author(s):  
Zifeng Liang
Keyword(s):  
Immune Response ◽  
Viral Infection ◽  
Mouse Models ◽  
Post Infection ◽  
Type I Interferon ◽  
Sendai Virus ◽  
Killer Cell ◽  
Type I ◽  
Respiratory Viral Infection ◽  
Neonatal Mice

The aim of this paper is to identify the difference of type I interferon expression in 2- day neonatal and six-to-eight-weeks adult mice infected by Sendai virus (SeV), a single- stranded RNA virus of the family Paramyxoviridae. Sendai virus mimics the influence of respiratory syncytial virus (RSV) on humans, but does not infect humans. Although RSV has a fatal impact on people across age groups, little is understood about this common virus and the disparity between neonatal and adult immune response to it. It has been suggested by past findings that Type I interferon mRNA is present in higher levels in adults than in neonates, however there is a greater amount of interferon proteins in neonates rather than adults. To test the hypothesis that neonates are more capable of interferon production and preventing the translation of viral protein, I observed mouse models of respiratory viral infection and determined the expression of IFN-α1, IFN-α2, IFN-α5, IFN-α6, IFN-α7, IFN-β in archived mouse lung tissue samples harvested on different days post-infection with quantitative real time PCR. Expression of Glyceraldehyde 3-phosphate dehydrogenase(GAPDH), a housekeeping gene expressed constitutively in all mouse models, was used as a positive control of the experiment. To determine the ideal concentration of primer used in qPCR, primer reconstitution, primer optimization, and gel electrophoresis were conducted in advance. In addition, technical replicates and biological replicates were used to reduce error and confirm results in qPCR. In accordance with previous discovery, I found an upward trend in adults’ interferon expression from post-infection day 1 to day 5, and levels off in day 7. In contrast, neonatal levels were much higher on day 1 and remained high over the course of infection. This explains how type I interferon expression is altered in neonates to help them clear the virus at the same efficiency as adults without causing inflammation. Future research on immune response differences in human infection should focus on the evaluation of interferon protein amounts, as well as the analysis of activation of molecules downstream of the type I interferon receptors, such as signal transducer and activator of transcription (STAT) protein family. It is also crucial to compare immune cells like macrophages and natural killer cell activity in adult and neonatal mice during viral infection.

scholarly journals High-Density Blood Transcriptomics Reveals Precision Immune Signatures of SARS-CoV-2 Infection in Hospitalized Individuals

2021 ◽  
Vol 12 ◽  
Author(s):  
Jeremy W. Prokop ◽  
Nicholas L. Hartog ◽  
Dave Chesla ◽  
William Faber ◽  
Chanise P. Love ◽  
...  
Keyword(s):  
Gene Expression ◽  
Immune Response ◽  
Viral Infections ◽  
Secretory Granules ◽  
Mitotic Cell ◽  
Hospitalized Patients ◽  
High Density ◽  
Type I ◽  
Secondary Infections ◽  
Blood Transcriptomics

The immune response to COVID-19 infection is variable. How COVID-19 influences clinical outcomes in hospitalized patients needs to be understood through readily obtainable biological materials, such as blood. We hypothesized that a high-density analysis of host (and pathogen) blood RNA in hospitalized patients with SARS-CoV-2 would provide mechanistic insights into the heterogeneity of response amongst COVID-19 patients when combined with advanced multidimensional bioinformatics for RNA. We enrolled 36 hospitalized COVID-19 patients (11 died) and 15 controls, collecting 74 blood PAXgene RNA tubes at multiple timepoints, one early and in 23 patients after treatment with various therapies. Total RNAseq was performed at high-density, with >160 million paired-end, 150 base pair reads per sample, representing the most sequenced bases per sample for any publicly deposited blood PAXgene tube study. There are 770 genes significantly altered in the blood of COVID-19 patients associated with antiviral defense, mitotic cell cycle, type I interferon signaling, and severe viral infections. Immune genes activated include those associated with neutrophil mechanisms, secretory granules, and neutrophil extracellular traps (NETs), along with decreased gene expression in lymphocytes and clonal expansion of the acquired immune response. Therapies such as convalescent serum and dexamethasone reduced many of the blood expression signatures of COVID-19. Severely ill or deceased patients are marked by various secondary infections, unique gene patterns, dysregulated innate response, and peripheral organ damage not otherwise found in the cohort. High-density transcriptomic data offers shared gene expression signatures, providing unique insights into the immune system and individualized signatures of patients that could be used to understand the patient’s clinical condition. Whole blood transcriptomics provides patient-level insights for immune activation, immune repertoire, and secondary infections that can further guide precision treatment.

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