scholarly journals Interferon-Stimulated Gene (ISG)-Expression Screening Reveals the Specific Antibunyaviral Activity of ISG20

2018 ◽  
Vol 92 (13) ◽  
Author(s):  
Junjie Feng ◽  
Arthur Wickenhagen ◽  
Matthew L. Turnbull ◽  
Veronica V. Rezelj ◽  
Felix Kreher ◽  
...  
Keyword(s):  
Viral Infections ◽  
Rhesus Macaques ◽  
Type I ◽  
Emerging Viruses ◽  
Content Type ◽  
Expression Screening ◽  
Interferon Stimulated Genes ◽  
Life Threatening

ABSTRACT Bunyaviruses pose a significant threat to human health, prosperity, and food security. In response to viral infections, interferons (IFNs) upregulate the expression of hundreds of interferon-stimulated genes (ISGs), whose cumulative action can potently inhibit the replication of bunyaviruses. We used a flow cytometry-based method to screen the ability of ∼500 unique ISGs from humans and rhesus macaques to inhibit the replication of Bunyamwera orthobunyavirus (BUNV), the prototype of both the Peribunyaviridae family and the Bunyavirales order. Candidates possessing antibunyaviral activity were further examined using a panel of divergent bunyaviruses. Interestingly, one candidate, ISG20, exhibited potent antibunyaviral activity against most viruses examined from the Peribunyaviridae , Hantaviridae , and Nairoviridae families, whereas phleboviruses ( Phenuiviridae ) largely escaped inhibition. Similar to the case against other viruses known to be targeted by ISG20, the antibunyaviral activity of ISG20 is dependent upon its functional RNase activity. Through use of an infectious virus-like particle (VLP) assay (based on the BUNV minigenome system), we confirmed that gene expression from all 3 viral segments is strongly inhibited by ISG20. Using in vitro evolution, we generated a substantially ISG20-resistant BUNV and mapped the determinants of ISG20 sensitivity/resistance. Taking all the data together, we report that ISG20 is a broad and potent antibunyaviral factor but that some bunyaviruses are remarkably ISG20 resistant. Thus, ISG20 sensitivity/resistance may influence the pathogenesis of bunyaviruses, many of which are emerging viruses of clinical or veterinary significance. IMPORTANCE There are hundreds of bunyaviruses, many of which cause life-threatening acute diseases in humans and livestock. The interferon (IFN) system is a key component of innate immunity, and type I IFNs limit bunyaviral propagation both in vitro and in vivo . Type I IFN signaling results in the upregulation of hundreds of IFN-stimulated genes (ISGs), whose concerted action generates an “antiviral state.” Although IFNs are critical in limiting bunyaviral replication and pathogenesis, much is still unknown about which ISGs inhibit bunyaviruses. Using ISG-expression screening, we examined the ability of ∼500 unique ISGs to inhibit Bunyamwera orthobunyavirus (BUNV), the prototypical bunyavirus. Using this approach, we identified ISG20, an interferon-stimulated exonuclease, as a potent inhibitor of BUNV. Interestingly, ISG20 possesses highly selective antibunyaviral activity, with multiple bunyaviruses being potently inhibited while some largely escape inhibition. We speculate that the ability of some bunyaviruses to escape ISG20 may influence their pathogenesis.

scholarly journals In Vitro Effects of Sulforaphane on Interferon-Driven Inflammation and Exploratory Evaluation in Two Healthy Volunteers

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3602
Author(s):  
Elena Genova ◽  
Maura Apollonio ◽  
Giuliana Decorti ◽  
Alessandra Tesser ◽  
Alberto Tommasini ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Supportive Therapy ◽  
P Value ◽  
Type I ◽  
Interferon Signature ◽  
Interferon Stimulated Genes ◽  
Immune System Activation ◽  
In Vitro Effects

Interferonopathies are rare genetic conditions defined by systemic inflammatory episodes caused by innate immune system activation in the absence of pathogens. Currently, no targeted drugs are authorized for clinical use in these diseases. In this work, we studied the contribution of sulforaphane (SFN), a cruciferous-derived bioactive molecule, in the modulation of interferon-driven inflammation in an immortalized human hepatocytes (IHH) line and in two healthy volunteers, focusing on STING, a key-component player in interferon pathway, interferon signature modulation, and GSTM1 expression and genotype, which contributes to SFN metabolism and excretion. In vitro, SFN exposure reduced STING expression as well as interferon signature in the presence of the pro-inflammatory stimulus cGAMP (cGAMP 3 h vs. SFN+cGAMP 3 h p value < 0.0001; cGAMP 6 h vs. SFN+cGAMP 6 h p < 0.001, one way ANOVA), restoring STING expression to the level of unstimulated cells. In preliminary experiments on healthy volunteers, no appreciable variations in interferon signature were identified after SFN assumption, while only in one of them, presenting the GSTM1 wild type genotype related to reduced SFN excretion, could a downregulation of STING be recorded. This study confirmed that SFN inhibits STING-mediated inflammation and interferon-stimulated genes expression in vitro. However, only a trend towards the downregulation of STING could be reproduced in vivo. Results obtained have to be confirmed in a larger group of healthy individuals and in patients with type I interferonopathies to define if the assumption of SFN could be useful as supportive therapy.

scholarly journals Transcriptional role of p53 in interferon-mediated antiviral immunity

2008 ◽  
Vol 205 (8) ◽  
pp. 1929-1938 ◽  
Author(s):  
César Muñoz-Fontela ◽  
Salvador Macip ◽  
Luis Martínez-Sobrido ◽  
Lauren Brown ◽  
Joseph Ashour ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Viral Replication ◽  
Viral Infections ◽  
Suppressor Gene ◽  
Central Component ◽  
Type I ◽  
Infected Cells

Tumor suppressor p53 is activated by several stimuli, including DNA damage and oncogenic stress. Previous studies (Takaoka, A., S. Hayakawa, H. Yanai, D. Stoiber, H. Negishi, H. Kikuchi, S. Sasaki, K. Imai, T. Shibue, K. Honda, and T. Taniguchi. 2003. Nature. 424:516–523) have shown that p53 is also induced in response to viral infections as a downstream transcriptional target of type I interferon (IFN) signaling. Moreover, many viruses, including SV40, human papillomavirus, Kaposi's sarcoma herpesvirus, adenoviruses, and even RNA viruses such as polioviruses, have evolved mechanisms designated to abrogate p53 responses. We describe a novel p53 function in the activation of the IFN pathway. We observed that infected mouse and human cells with functional p53 exhibited markedly decreased viral replication early after infection. This early inhibition of viral replication was mediated both in vitro and in vivo by a p53-dependent enhancement of IFN signaling, specifically the induction of genes containing IFN-stimulated response elements. Of note, p53 also contributed to an increase in IFN release from infected cells. We established that this p53-dependent enhancement of IFN signaling is dependent to a great extent on the ability of p53 to activate the transcription of IFN regulatory factor 9, a central component of the IFN-stimulated gene factor 3 complex. Our results demonstrate that p53 contributes to innate immunity by enhancing IFN-dependent antiviral activity independent of its functions as a proapoptotic and tumor suppressor gene.

scholarly journals Assessment of Mycobacterium tuberculosis Pantothenate Kinase Vulnerability through Target Knockdown and Mechanistically Diverse Inhibitors

2014 ◽  
Vol 58 (6) ◽  
pp. 3312-3326 ◽  
Author(s):  
B. K. Kishore Reddy ◽  
Sudhir Landge ◽  
Sudha Ravishankar ◽  
Vikas Patil ◽  
Vikas Shinde ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Present Report ◽  
Kinetic Studies ◽  
Antimycobacterial Activity ◽  
Type I ◽  
Pantothenate Kinase ◽  
Content Type ◽  
Rate Limiting Step

ABSTRACTPantothenate kinase (PanK) catalyzes the phosphorylation of pantothenate, the first committed and rate-limiting step toward coenzyme A (CoA) biosynthesis. In our earlier reports, we had established that the type I isoform encoded by thecoaAgene is an essential pantothenate kinase inMycobacterium tuberculosis, and this vital information was then exploited to screen large libraries for identification of mechanistically different classes of PanK inhibitors. The present report summarizes the synthesis and expansion efforts to understand the structure-activity relationships leading to the optimization of enzyme inhibition along with antimycobacterial activity. Additionally, we report the progression of two distinct classes of inhibitors, the triazoles, which are ATP competitors, and the biaryl acetic acids, with a mixed mode of inhibition. Cocrystallization studies provided evidence of these inhibitors binding to the enzyme. This was further substantiated with the biaryl acids having MIC against the wild-typeM. tuberculosisstrain and the subsequent establishment of a target link with an upshift in MIC in a strain overexpressing PanK. On the other hand, the ATP competitors had cellular activity only in aM. tuberculosisknockdown strain with reduced PanK expression levels. Additionally,in vitroandin vivosurvival kinetic studies performed with aM. tuberculosisPanK (MtPanK) knockdown strain indicated that the target levels have to be significantly reduced to bring in growth inhibition. The dual approaches employed here thus established the poor vulnerability of PanK inM. tuberculosis.

scholarly journals Hydroxylamine and Carboxymethoxylamine Can Inhibit Toxoplasma gondii Growth through an Aspartate Aminotransferase-Independent Pathway

2020 ◽  
Vol 64 (3) ◽  
Author(s):  
Jixu Li ◽  
Huanping Guo ◽  
Eloiza May Galon ◽  
Yang Gao ◽  
Seung-Hun Lee ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Drug Targets ◽  
Protozoan Parasite ◽  
Cell Types ◽  
Lytic Cycle ◽  
Type I ◽  
Content Type ◽  
Mechanism Of Inhibition

ABSTRACT Toxoplasma gondii is an obligate intracellular protozoan parasite and a successful parasitic pathogen in diverse organisms and host cell types. Hydroxylamine (HYD) and carboxymethoxylamine (CAR) have been reported as inhibitors of aspartate aminotransferases (AATs) and interfere with the proliferation in Plasmodium falciparum. Therefore, AATs are suggested as drug targets against Plasmodium. The T. gondii genome encodes only one predicted AAT in both T. gondii type I strain RH and type II strain PLK. However, the effects of HYD and CAR, as well as their relationship with AAT, on T. gondii remain unclear. In this study, we found that HYD and CAR impaired the lytic cycle of T. gondii in vitro, including the inhibition of invasion or reinvasion, intracellular replication, and egress. Importantly, HYD and CAR could control acute toxoplasmosis in vivo. Further studies showed that HYD and CAR could inhibit the transamination activity of rTgAAT in vitro. However, our results confirmed that deficiency of AAT in both RH and PLK did not reduce the virulence in mice, although the growth ability of the parasites was affected in vitro. HYD and CAR could still inhibit the growth of AAT-deficient parasites. These findings indicated that HYD and CAR inhibition of T. gondii growth and control of toxoplasmosis can occur in an AAT-independent pathway. Overall, further studies focusing on the elucidation of the mechanism of inhibition are warranted. Our study hints at new substrates of HYD and CAR as potential drug targets to inhibit T. gondii growth.

scholarly journals Positive regulation of plasmacytoid dendritic cell function via Ly49Q recognition of class I MHC

2008 ◽  
Vol 205 (13) ◽  
pp. 3187-3199 ◽  
Author(s):  
Lee-Hwa Tai ◽  
Marie-Line Goulet ◽  
Simon Belanger ◽  
Noriko Toyama-Sorimachi ◽  
Nassima Fodil-Cornu ◽  
...  
Keyword(s):  
Immune Responses ◽  
Cell Function ◽  
Viral Infections ◽  
Plasmacytoid Dendritic Cell ◽  
Class I ◽  
Type I ◽  
Class I Mhc ◽  
Mhc Molecules

Plasmacytoid dendritic cells (pDCs) are an important source of type I interferon (IFN) during initial immune responses to viral infections. In mice, pDCs are uniquely characterized by high-level expression of Ly49Q, a C-type lectin-like receptor specific for class I major histocompatibility complex (MHC) molecules. Despite having a cytoplasmic immunoreceptor tyrosine-based inhibitory motif, Ly49Q was found to enhance pDC function in vitro, as pDC cytokine production in response to the Toll-like receptor (TLR) 9 agonist CpG-oligonucleotide (ODN) could be blocked using soluble monoclonal antibody (mAb) to Ly49Q or H-2Kb. Conversely, CpG-ODN–dependent IFN-α production by pDCs was greatly augmented upon receptor cross-linking using immobilized anti-Ly49Q mAb or recombinant H-2Kb ligand. Accordingly, Ly49Q-deficient pDCs displayed a severely reduced capacity to produce cytokines in response to TLR7 and TLR9 stimulation both in vitro and in vivo. Finally, TLR9-dependent antiviral responses were compromised in Ly49Q-null mice infected with mouse cytomegalovirus. Thus, class I MHC recognition by Ly49Q on pDCs is necessary for optimal activation of innate immune responses in vivo.

scholarly journals The Use of Antimalarial Drugs against Viral Infection

2020 ◽  
Vol 8 (1) ◽  
pp. 85 ◽  
Author(s):  
Sarah D’Alessandro ◽  
Diletta Scaccabarozzi ◽  
Lucia Signorini ◽  
Federica Perego ◽  
Denise P. Ilboudo ◽  
...  
Keyword(s):  
Ebola Virus ◽  
Viral Infections ◽  
Antimalarial Drugs ◽  
Drug Resistant ◽  
Emerging Viruses ◽  
Antimicrobial Drugs ◽  
Artemisinin Derivatives ◽  
Antiviral Activities

In recent decades, drugs used to treat malaria infection have been shown to be beneficial for many other diseases, including viral infections. In particular, they have received special attention due to the lack of effective antiviral drugs against new emerging viruses (i.e., HIV, dengue virus, chikungunya virus, Ebola virus, etc.) or against classic infections due to drug-resistant viral strains (i.e., human cytomegalovirus). Here, we reviewed the in vitro/in vivo and clinical studies conducted to evaluate the antiviral activities of four classes of antimalarial drugs: Artemisinin derivatives, aryl-aminoalcohols, aminoquinolines, and antimicrobial drugs.

scholarly journals TRIM35 mediates protection against influenza infection by activating TRAF3 and degrading viral PB2

2020 ◽  
Vol 11 (12) ◽  
pp. 894-914
Author(s):  
Nan Sun ◽  
Li Jiang ◽  
Miaomiao Ye ◽  
Yihan Wang ◽  
Guangwen Wang ◽  
...  
Keyword(s):  
Influenza A ◽  
Viral Infections ◽  
Influenza Infection ◽  
Type I ◽  
Subsequent Formation ◽  
Antiviral Immune Response ◽  
Signaling Complex ◽  
Deficient Mice

AbstractTripartite motif (TRIM) family proteins are important effectors of innate immunity against viral infections. Here we identified TRIM35 as a regulator of TRAF3 activation. Deficiency in or inhibition of TRIM35 suppressed the production of type I interferon (IFN) in response to viral infection. Trim35-deficient mice were more susceptible to influenza A virus (IAV) infection than were wild-type mice. TRIM35 promoted the RIG-I-mediated signaling by catalyzing Lys63-linked polyubiquitination of TRAF3 and the subsequent formation of a signaling complex with VISA and TBK1. IAV PB2 polymerase countered the innate antiviral immune response by impeding the Lys63-linked polyubiquitination and activation of TRAF3. TRIM35 mediated Lys48-linked polyubiquitination and proteasomal degradation of IAV PB2, thereby antagonizing its suppression of TRAF3 activation. Our in vitro and in vivo findings thus reveal novel roles of TRIM35, through catalyzing Lys63- or Lys48-linked polyubiquitination, in RIG-I antiviral immunity and mechanism of defense against IAV infection.

scholarly journals Broadening the Spectrum of β-Lactam Antibiotics through Inhibition of Signal Peptidase Type I

2012 ◽  
Vol 56 (9) ◽  
pp. 4662-4670 ◽  
Author(s):  
Alex G. Therien ◽  
Joann L. Huber ◽  
Kenneth E. Wilson ◽  
Patrick Beaulieu ◽  
Alexandre Caron ◽  
...  
Keyword(s):  
Treatment Options ◽  
Signal Peptidase ◽  
Type I ◽  
New Agents ◽  
Content Type ◽  
Cyclic Depsipeptide ◽  
Serious Infections ◽  
Synthetic Derivative

ABSTRACTThe resistance of methicillin-resistantStaphylococcus aureus(MRSA) to all β-lactam classes limits treatment options for serious infections involving this organism. Our goal is to discover new agents that restore the activity of β-lactams against MRSA, an approach that has led to the discovery of two classes of natural product antibiotics, a cyclic depsipeptide (krisynomycin) and a lipoglycopeptide (actinocarbasin), which potentiate the activity of imipenem against MRSA strain COL. We report here that these imipenem synergists are inhibitors of the bacterial type I signal peptidase SpsB, a serine protease that is required for the secretion of proteins that are exported through the Sec and Tat systems. A synthetic derivative of actinocarbasin, M131, synergized with imipenem bothin vitroandin vivowith potent efficacy. Thein vitroactivity of M131 extends to clinical isolates of MRSA but not to a methicillin-sensitive strain. Synergy is restricted to β-lactam antibiotics and is not observed with other antibiotic classes. We propose that the SpsB inhibitors synergize with β-lactams by preventing the signal peptidase-mediated secretion of proteins required for β-lactam resistance. Combinations of SpsB inhibitors and β-lactams may expand the utility of these widely prescribed antibiotics to treat MRSA infections, analogous to β-lactamase inhibitors which restored the utility of this antibiotic class for the treatment of resistant Gram-negative infections.

scholarly journals PI4 Kinase Is a Prophylactic but Not Radical Curative Target in Plasmodium vivax-Type Malaria Parasites

2016 ◽  
Vol 60 (5) ◽  
pp. 2858-2863 ◽  
Author(s):  
Anne-Marie Zeeman ◽  
Suresh B. Lakshminarayana ◽  
Nicole van der Werff ◽  
Els J. Klooster ◽  
Annemarie Voorberg-van der Wel ◽  
...  
Keyword(s):  
Drug Target ◽  
Rhesus Macaques ◽  
Secondary Infection ◽  
Pharmacokinetic Data ◽  
Radical Cure ◽  
Plasma Exposure ◽  
Content Type ◽  
Plasmodium Cynomolgi

ABSTRACTTwoPlasmodiumPI4 kinase (PI4K) inhibitors, KDU691 and LMV599, were selected forin vivotesting as causal prophylactic and radical-cure agents forPlasmodium cynomolgisporozoite-infected rhesus macaques, based on theirin vitroactivity against liver stages. Animals were infected withP. cynomolgisporozoites, and compounds were dosed orally. Both the KDU691 and LMV599 compounds were fully protective when administered prophylactically, and the more potent compound LMV599 achieved protection as a single oral dose of 25 mg/kg of body weight. In contrast, when tested for radical cure, five daily doses of 20 mg/kg of KDU691 or 25 mg/kg of LMV599 did not prevent relapse, as all animals experienced a secondary infection due to the reactivation of hypnozoites in the liver. Pharmacokinetic data show that LMV599 achieved plasma exposure that was sufficient to achieve efficacy based on ourin vitrodata. These findings indicate thatPlasmodiumPI4K is a potential drug target for malaria prophylaxis but not radical cure. Longerin vitroculture systems will be required to assess these compounds' activity on established hypnozoites and predict radical curein vivo.

scholarly journals Guanabenz Repurposed as an Antiparasitic with Activity against Acute and Latent Toxoplasmosis

2015 ◽  
Vol 59 (11) ◽  
pp. 6939-6945 ◽  
Author(s):  
Imaan Benmerzouga ◽  
Lisa A. Checkley ◽  
Michael T. Ferdig ◽  
Gustavo Arrizabalaga ◽  
Ronald C. Wek ◽  
...  
Keyword(s):  
Translational Control ◽  
Protozoan Parasite ◽  
Empty Space ◽  
Antiparasitic Activity ◽  
Content Type ◽  
Life Threatening ◽  
Brain Cysts ◽  
The Brain

ABSTRACTToxoplasma gondiiis a protozoan parasite that persists as a chronic infection.Toxoplasmaevades immunity by forming tissue cysts, which reactivate to cause life-threatening disease during immune suppression. There is an urgent need to identify drugs capable of targeting these latent tissue cysts, which tend to form in the brain. We previously showed that translational control is critical during infections with both replicative and latent forms ofToxoplasma. Here we report that guanabenz, an FDA-approved drug that interferes with translational control, has antiparasitic activity against replicative stages ofToxoplasmaand the related apicomplexan parasitePlasmodium falciparum(a malaria agent). We also found that inhibition of translational control interfered with tissue cyst biologyin vitro.Toxoplasmabradyzoites present in these abnormal cysts were diminished and misconfigured, surrounded by empty space not seen in normal cysts. These findings prompted analysis of the efficacy of guanabenzin vivoby using established mouse models of acute and chronic toxoplasmosis. In addition to protecting mice from lethal doses ofToxoplasma, guanabenz has a remarkable ability to reduce the number of brain cysts in chronically infected mice. Our findings suggest that guanabenz can be repurposed into an effective antiparasitic with a unique ability to reduce tissue cysts in the brain.

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