scholarly journals Autophagy Contributes to Host Immunity and Protection against Zika Virus Infection via Type I IFN Signaling

2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Yuyi Huang ◽  
Yujie Wang ◽  
Shuhui Meng ◽  
Zhuohang Chen ◽  
Haifan Kong ◽  
...  
Keyword(s):  
Virus Infection ◽  
Cell Line ◽  
Zika Virus ◽  
Fetal Brain ◽  
Host Immunity ◽  
Type I ◽  
Type I Ifn ◽  
Zikv Infection

Recent studies have indicated that the Zika virus (ZIKV) has a significant impact on the fetal brain, and autophagy is contributing to host immune response and defense against virus infection. Here, we demonstrate that ZIKV infection triggered increased LC3 punctuation in mouse monocyte-macrophage cell line (RAW264.7), mouse microglial cell line (BV2), and hindbrain tissues, proving the occurrence of autophagy both in vitro and in vivo. Interestingly, manual intervention of autophagy, like deficiency inhibited by 3-MA, can reduce viral clearance in RAW264.7 cells upon ZIKV infection. Besides, specific siRNA strategy confirmed that autophagy can be activated through Atg7-Atg5 and type I IFN signaling pathway upon ZIKV infection, while knocking down of Atg7 and Atg5 effectively decreased the ZIKV clearance in phagocytes. Furthermore, we analyzed that type I IFN signaling could contribute to autophagic clearance of invaded ZIKV in phagocytes. Taken together, our findings demonstrate that ZIKV-induced autophagy is favorable to activate host immunity, particularly through type I IFN signaling, which participates in host protection and defense against ZIKV infection.

scholarly journals The Ability of Zika virus Intravenous Immunoglobulin to Protect From or Enhance Zika Virus Disease

2021 ◽  
Vol 12 ◽  
Author(s):  
Amelia K. Pinto ◽  
Mariah Hassert ◽  
Xiaobing Han ◽  
Douglas Barker ◽  
Trevor Carnelley ◽  
...  
Keyword(s):  
Virus Infection ◽  
Polyclonal Antibody ◽  
Zika Virus ◽  
Virus Disease ◽  
Polyclonal Antibodies ◽  
Antibody Therapeutics ◽  
The World ◽  
Flavivirus Infection

The closely related flaviviruses, dengue and Zika, cause significant human disease throughout the world. While cross-reactive antibodies have been demonstrated to have the capacity to potentiate disease or mediate protection during flavivirus infection, the mechanisms responsible for this dichotomy are still poorly understood. To understand how the human polyclonal antibody response can protect against, and potentiate the disease in the context of dengue and Zika virus infection we used intravenous hyperimmunoglobulin (IVIG) preparations in a mouse model of the disease. Three IVIGs (ZIKV-IG, Control-Ig and Gamunex®) were evaluated for their ability to neutralize and/or enhance Zika, dengue 2 and 3 viruses in vitro. The balance between virus neutralization and enhancement provided by the in vitro neutralization data was used to predict the IVIG concentrations which could protect or enhance Zika, and dengue 2 disease in vivo. Using this approach, we were able to define the unique in vivo dynamics of complex polyclonal antibodies, allowing for both enhancement and protection from flavivirus infection. Our results provide a novel understanding of how polyclonal antibodies interact with viruses with implications for the use of polyclonal antibody therapeutics and the development and evaluation of the next generation flavivirus vaccines.

scholarly journals Innate triggering and antiviral effector functions of activin A

2021 ◽  
Author(s):  
Kinda Al-Hourani ◽  
Narayan Ramamurthy ◽  
Emanuele Marchi ◽  
Ruth M Eichinger ◽  
Lian N Lee ◽  
...  
Keyword(s):  
Viral Infection ◽  
Influenza A ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Activin A ◽  
Type I ◽  
Type I Ifn ◽  
Effector Functions

First-line defence against viral infection is contingent upon rapid detection of conserved viral structural and genomic motifs by germline-encoded pattern recognition receptors, followed by activation of the type I IFN system and establishment of an intracellular antiviral state. Novel antiviral functions of bone morphogenetic protein and related activin cytokines, acting in conjunction with, and independently of, type I IFN, have recently been described. Activin A mediates multiple innate and adaptive immune functions, including antiviral effects. However, how such effects are mediated and how activin might be triggered by viral infection have not been defined. Here we addressed this in vivo and in vitro, in humans and mice. Transcriptomic analyses delineated strikingly congruent patterns of gene regulation in hepatocytes stimulated with recombinant activin A and IFNα in vitro. Activin A mRNA, encoded by INHBA, is induced upon activation of RIG-I, MDA5 and TLR7/8 viral nucleic acid sensors in vitro, across multiple cell lines and in human peripheral blood mononuclear cells. In vivo, infection of mice with influenza A also upregulated Inhba mRNA in the lung; this local upregulation of Inhba is retained in MAVS knockout mice, indicating a role for non-RIG-I-like receptors in its induction. Activin induction and signalling were also detectable in patients with chronic viral hepatitis. Together, these data suggest Activin A is triggered in parallel with type I IFN responses and can trigger related antiviral effector functions. This model has implications for the development of targeted antiviral therapies, in addition to revealing novel facets of activin biology.

scholarly journals Revisiting the role of IRF3 in inflammation and immunity by conditional and specifically targeted gene ablation in mice

2018 ◽  
Vol 115 (20) ◽  
pp. 5253-5258 ◽  
Author(s):  
Hideyuki Yanai ◽  
Shiho Chiba ◽  
Sho Hangai ◽  
Kohei Kometani ◽  
Asuka Inoue ◽  
...  
Keyword(s):  
Immune Cell ◽  
Cell Types ◽  
Type I ◽  
Type I Ifn ◽  
Cell Type ◽  
Gene Ablation ◽  
Cell Type Specific

IFN regulatory factor 3 (IRF3) is a transcription regulator of cellular responses in many cell types that is known to be essential for innate immunity. To confirm IRF3’s broad role in immunity and to more fully discern its role in various cellular subsets, we engineered Irf3-floxed mice to allow for the cell type-specific ablation of Irf3. Analysis of these mice confirmed the general requirement of IRF3 for the evocation of type I IFN responses in vitro and in vivo. Furthermore, immune cell ontogeny and frequencies of immune cell types were unaffected when Irf3 was selectively inactivated in either T cells or B cells in the mice. Interestingly, in a model of lipopolysaccharide-induced septic shock, selective Irf3 deficiency in myeloid cells led to reduced levels of type I IFN in the sera and increased survival of these mice, indicating the myeloid-specific, pathogenic role of the Toll-like receptor 4–IRF3 type I IFN axis in this model of sepsis. Thus, Irf3-floxed mice can serve as useful tool for further exploring the cell type-specific functions of this transcription factor.

scholarly journals JMX0207, a Niclosamide Derivative with Improved Pharmacokinetics, Suppresses Zika Virus Infection Both In Vitro and In Vivo

2020 ◽  
Vol 6 (10) ◽  
pp. 2616-2628 ◽  
Author(s):  
Zhong Li ◽  
Jimin Xu ◽  
Yuekun Lang ◽  
Xiaoyu Fan ◽  
Lili Kuo ◽  
...  
Keyword(s):  
Virus Infection ◽  
Zika Virus ◽  
Zika Virus Infection

scholarly journals Animal Models of Zika Virus Infection during Pregnancy

Viruses ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 598 ◽  
Author(s):  
Elizabeth Caine ◽  
Brett Jagger ◽  
Michael Diamond
Keyword(s):  
Animal Models ◽  
Virus Infection ◽  
Zika Virus ◽  
Reproductive Tract ◽  
Congenital Abnormalities ◽  
Tissue Tropism ◽  
Zikv Infection ◽  
In Vivo Models ◽  
Sexually Transmitted

Zika virus (ZIKV) emerged suddenly in the Americas in 2015 and was associated with a widespread outbreak of microcephaly and other severe congenital abnormalities in infants born to mothers infected during pregnancy. Vertical transmission of ZIKV in humans was confirmed when viral RNA was detected in fetal and placental tissues, and this outcome has been recapitulated experimentally in animals. Unlike other flaviviruses, ZIKV is both arthropod- and sexually-transmitted, and has a broad tissue tropism in humans, including multiple tissues of the reproductive tract. The threats posed by ZIKV have prompted the development of multiple in vivo models to better understand the pathogenesis of ZIKV, particularly during pregnancy. Here, we review the progress on animal models of ZIKV infection during pregnancy. These studies have generated a foundation of insights into the biology of ZIKV, and provide a means for evaluating vaccines and therapeutics.

scholarly journals Interferon Regulatory Factor IRF-7 Induces the Antiviral Alpha Interferon Response and Protects against Lethal West Nile Virus Infection

2008 ◽  
Vol 82 (17) ◽  
pp. 8465-8475 ◽  
Author(s):  
Stephane Daffis ◽  
Melanie A. Samuel ◽  
Mehul S. Suthar ◽  
Brian C. Keller ◽  
Michael Gale ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Cortical Neurons ◽  
Interferon Regulatory Factor ◽  
Interferon Response ◽  
Type I ◽  
Type I Ifn ◽  
Regulatory Factor ◽  
West Nile

ABSTRACT Type I interferon (IFN-α/β) comprises a family of immunomodulatory cytokines that are critical for controlling viral infections. In cell culture, many RNA viruses trigger IFN responses through the binding of RNA recognition molecules (RIG-I, MDA5, and TLR-3) and induction of interferon regulatory factor IRF-3-dependent gene transcription. Recent studies with West Nile virus (WNV) have shown that type I IFN is essential for restricting infection and that a deficiency of IRF-3 results in enhanced lethality. However, IRF-3 was not required for optimal systemic IFN production in vivo or in vitro in macrophages. To begin to define the transcriptional factors that regulate type I IFN after WNV infection, we evaluated IFN induction and virus control in IRF-7−/− mice. Compared to congenic wild-type mice, IRF-7−/− mice showed increased lethality after WNV infection and developed early and elevated WNV burdens in both peripheral and central nervous system tissues. As a correlate, a deficiency of IRF-7 blunted the systemic type I IFN response in mice. Consistent with this, IFN-α gene expression and protein production were reduced and viral titers were increased in IRF-7−/− primary macrophages, fibroblasts, dendritic cells, and cortical neurons. In contrast, in these cells the IFN-β response remained largely intact. Our data suggest that the early protective IFN-α response against WNV occurs through an IRF-7-dependent transcriptional signal.

scholarly journals ORF7-encoded accessory protein 7a of feline infectious peritonitis virus as a counteragent against IFN-α-induced antiviral response

2014 ◽  
Vol 95 (2) ◽  
pp. 393-402 ◽  
Author(s):  
Annelike Dedeurwaerder ◽  
Dominique A. J. Olyslaegers ◽  
Lowiese M. B. Desmarets ◽  
Inge D. M. Roukaerts ◽  
Sebastiaan Theuns ◽  
...  
Keyword(s):  
Antiviral Response ◽  
Replication Capacity ◽  
Type I ◽  
Type I Ifn ◽  
Feline Infectious Peritonitis Virus ◽  
Feline Infectious Peritonitis ◽  
Efficient Replication ◽  
In Trans

The type I IFN-mediated immune response is the first line of antiviral defence. Coronaviruses, like many other viruses, have evolved mechanisms to evade this innate response, ensuring their survival. Several coronavirus accessory genes play a central role in these pathways, but for feline coronaviruses this has never to our knowledge been studied. As it has been demonstrated previously that ORF7 is essential for efficient replication in vitro and virulence in vivo of feline infectious peritonitis virus (FIPV), the role of this ORF in the evasion of the IFN-α antiviral response was investigated. Deletion of ORF7 from FIPV strain 79-1146 (FIPV-Δ7) rendered the virus more susceptible to IFN-α treatment. Given that ORF7 encodes two proteins, 7a and 7b, it was further explored which of these proteins is active in this mechanism. Providing 7a protein in trans rescued the mutant FIPV-Δ7 from IFN sensitivity, which was not achieved by addition of 7b protein. Nevertheless, addition of protein 7a to FIPV-Δ3Δ7, a FIPV mutant deleted in both ORF3 and ORF7, could no longer increase the replication capacity of this mutant in the presence of IFN. These results indicate that FIPV 7a protein is a type I IFN antagonist and protects the virus from the antiviral state induced by IFN, but it needs the presence of ORF3-encoded proteins to exert its antagonistic function.

scholarly journals N-Methyl-d-Aspartate (NMDA) Receptor Blockade Prevents Neuronal Death Induced by Zika Virus Infection

mBio ◽  
2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Vivian V. Costa ◽  
Juliana L. Del Sarto ◽  
Rebeca F. Rocha ◽  
Flavia R. Silva ◽  
Juliana G. Doria ◽  
...  
Keyword(s):  
Global Health ◽  
Drug Treatment ◽  
Zika Virus ◽  
Neuronal Death ◽  
Neuronal Damage ◽  
Neurological Complications ◽  
Zikv Infection ◽  
Experimental Animals

ABSTRACT Zika virus (ZIKV) infection is a global health emergency that causes significant neurodegeneration. Neurodegenerative processes may be exacerbated by N-methyl-d-aspartate receptor (NMDAR)-dependent neuronal excitoxicity. Here, we have exploited the hypothesis that ZIKV-induced neurodegeneration can be rescued by blocking NMDA overstimulation with memantine. Our results show that ZIKV actively replicates in primary neurons and that virus replication is directly associated with massive neuronal cell death. Interestingly, treatment with memantine or other NMDAR blockers, including dizocilpine (MK-801), agmatine sulfate, or ifenprodil, prevents neuronal death without interfering with the ability of ZIKV to replicate in these cells. Moreover, in vivo experiments demonstrate that therapeutic memantine treatment prevents the increase of intraocular pressure (IOP) induced by infection and massively reduces neurodegeneration and microgliosis in the brain of infected mice. Our results indicate that the blockade of NMDARs by memantine provides potent neuroprotective effects against ZIKV-induced neuronal damage, suggesting it could be a viable treatment for patients at risk for ZIKV infection-induced neurodegeneration. IMPORTANCE Zika virus (ZIKV) infection is a global health emergency associated with serious neurological complications, including microcephaly and Guillain-Barré syndrome. Infection of experimental animals with ZIKV causes significant neuronal damage and microgliosis. Treatment with drugs that block NMDARs prevented neuronal damage both in vitro and in vivo. These results suggest that overactivation of NMDARs contributes significantly to the neuronal damage induced by ZIKV infection, and this is amenable to inhibition by drug treatment. IMPORTANCE Zika virus (ZIKV) infection is a global health emergency associated with serious neurological complications, including microcephaly and Guillain-Barré syndrome. Infection of experimental animals with ZIKV causes significant neuronal damage and microgliosis. Treatment with drugs that block NMDARs prevented neuronal damage both in vitro and in vivo. These results suggest that overactivation of NMDARs contributes significantly to the neuronal damage induced by ZIKV infection, and this is amenable to inhibition by drug treatment.

Type I interferons produced by dendritic cells promote their phenotypic and functional activation

Blood ◽  
2002 ◽  
Vol 99 (9) ◽  
pp. 3263-3271 ◽  
Author(s):  
Maria Montoya ◽  
Giovanna Schiavoni ◽  
Fabrizio Mattei ◽  
Ion Gresser ◽  
Filippo Belardelli ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dendritic Cells ◽  
T Cell ◽  
Bone Marrow Cells ◽  
Type I Interferons ◽  
Type I ◽  
Type I Ifn ◽  
Type I Ifns

Abstract Resting dendritic cells (DCs) are resident in most tissues and can be activated by environmental stimuli to mature into potent antigen-presenting cells. One important stimulus for DC activation is infection; DCs can be triggered through receptors that recognize microbial components directly or by contact with infection-induced cytokines. We show here that murine DCs undergo phenotypic maturation upon exposure to type I interferons (type I IFNs) in vivo or in vitro. Moreover, DCs either derived from bone marrow cells in vitro or isolated from the spleens of normal animals express IFN-α and IFN-β, suggesting that type I IFNs can act in an autocrine manner to activate DCs. Consistent with this idea, the ability to respond to type I IFN was required for the generation of fully activated DCs from bone marrow precursors, as DCs derived from the bone marrow of mice lacking a functional receptor for type I IFN had reduced expression of costimulatory and adhesion molecules and a diminished ability to stimulate naive T-cell proliferation compared with DCs derived from control bone marrow. Furthermore, the addition of neutralizing anti–IFN-α/β antibody to purified splenic DCs in vitro partially blocked the “spontaneous” activation of these cells, inhibiting the up-regulation of costimulatory molecules, secretion of IFN-γ, and T-cell stimulatory activity. These results show that DCs both secrete and respond to type I IFN, identifying type I interferons as autocrine DC activators.

scholarly journals The stronger downregulation of in vitro and in vivo innate antiviral responses by a very virulent strain of infectious bursal disease virus (IBDV), compared to a classical strain, is mediated, in part, by the VP4 protein

2019 ◽  
Author(s):  
KL Dulwich ◽  
AS Asfor ◽  
AG Gray ◽  
ES Giotis ◽  
MA Skinner ◽  
...  
Keyword(s):  
Virulent Strain ◽  
Bursa Of Fabricius ◽  
Luciferase Reporter ◽  
Type I ◽  
Type I Ifn ◽  
Lower Survival Rate ◽  
Classical Strain ◽  
In Cells

AbstractIBDV is economically important to the poultry industry. Very virulent (vv) strains cause higher mortality rates than other strains for reasons that remain poorly understood. In order to provide more information on IBDV disease outcome, groups of chickens (n=18) were inoculated with the vv strain, UK661, or the classical strain, F52/70. Birds infected with UK661 had a lower survival rate (50%) compared to F52/70 (80%). There was no difference in peak viral replication in the bursa of Fabricius (BF), but the expression of chicken IFNβ, MX1 and IL-8 was significantly lower in the BF of birds infected with UK661 compared to F52/70 (p<0.05) as quantified by RTqPCR, and this trend was also observed in DT40 cells infected with UK661 or F52/70 (p<0.05). The induction of expression of type I IFN in DF-1 cells stimulated with polyI:C (measured by an IFN-β luciferase reporter assay) was significantly reduced in cells expressing ectopic VP4 from UK661 (p<0.05), but was higher in cells expressing ectopic VP4 from F52/70. Cells infected with a chimeric recombinant IBDV carrying the UK661-VP4 gene in the background of PBG98, an attenuated vaccine strain that induces high levels of innate responses (PBG98-VP4UK661) also showed a reduced level of IFNα and IL-8 compared to cells infected with a chimeric virus carrying the F52/70-VP4 gene (PBG98-VP4F52/70), and birds infected with PBG98-VP4UK661 also had a reduced expression of IFNα in the BF compared to birds infected with PBG98-VP4F52/70. Taken together, these data demonstrate that UK661 induced the expression of lower levels of anti-viral type I IFN and proinflammatory genes than the classical strain in vitro and in vivo and this was, in part, due to strain-dependent differences in the VP4 protein.

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