scholarly journals Novel Ionophores Active against La Crosse Virus Identified through Rapid Antiviral Screening

2020 ◽  
Vol 64 (6) ◽  
Author(s):  
Zachary J. Sandler ◽  
Mason R. Firpo ◽  
Oreoluwa S. Omoba ◽  
Michelle N. Vu ◽  
Vineet D. Menachery ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Virus Replication ◽  
Viral Infections ◽  
Rift Valley Fever Virus ◽  
Virus Titer ◽  
Potassium Ions ◽  
Dependent Manner ◽  
La Crosse Virus ◽  
Human Pathogens ◽  
Valley Fever

ABSTRACT Bunyaviruses are significant human pathogens, causing diseases ranging from hemorrhagic fevers to encephalitis. Among these viruses, La Crosse virus (LACV), a member of the California serogroup, circulates in the eastern and midwestern United States. While LACV infection is often asymptomatic, dozens of cases of encephalitis are reported yearly. Unfortunately, no antivirals have been approved to treat LACV infection. Here, we developed a method to rapidly test potential antivirals against LACV infection. From this screen, we identified several potential antiviral molecules, including known antivirals. Additionally, we identified many novel antivirals that exhibited antiviral activity without affecting cellular viability. Valinomycin, a potassium ionophore, was among our top targets. We found that valinomycin exhibited potent anti-LACV activity in multiple cell types in a dose-dependent manner. Valinomycin did not affect particle stability or infectivity, suggesting that it may preclude virus replication by altering cellular potassium ions, a known determinant of LACV entry. We extended these results to other ionophores and found that the antiviral activity of valinomycin extended to other viral families, including bunyaviruses (Rift Valley fever virus, Keystone virus), enteroviruses (coxsackievirus, rhinovirus), flavirivuses (Zika virus), and coronaviruses (human coronavirus 229E [HCoV-229E] and Middle East respiratory syndrome CoV [MERS-CoV]). In all viral infections, we observed significant reductions in virus titer in valinomycin-treated cells. In sum, we demonstrate the importance of potassium ions to virus infection, suggesting a potential therapeutic target to disrupt virus replication.

scholarly journals Novel ionophores active against La Crosse virus identified through rapid antiviral screening

2020 ◽  
Author(s):  
Zachary J. Sandler ◽  
Michelle N. Vu ◽  
Vineet D. Menachery ◽  
Bryan C. Mounce
Keyword(s):  
Virus Infection ◽  
Antiviral Activity ◽  
Virus Replication ◽  
Rift Valley Fever Virus ◽  
Ion Homeostasis ◽  
Virus Titer ◽  
Potassium Ions ◽  
Dependent Manner ◽  
La Crosse Virus ◽  
Human Pathogens

AbstractBunyaviruses are significant human pathogens, causing diseases ranging from hemorrhagic fevers to encephalitis. Among these viruses, La Crosse virus (LACV), a member of the California serogroup, circulates in the eastern and midwestern United States. While LACV infection is often asymptomatic, dozens of cases of encephalitis are reported yearly. Unfortunately, no antivirals have been approved to treat LACV infection. Here, we developed a method to rapidly test potential antivirals against LACV infection. From this screen, we identified several potential antiviral molecules, including known antivirals. Additionally, we identified many novel antivirals that exhibited antiviral activity without affecting cellular viability. Valinomycin, a potassium ionophore, was among our top targets. We found that valinomycin exhibited potent anti-LACV activity in multiple cell types in a dose-dependent manner. Valinomycin did not affect particle stability or infectivity, suggesting that it may preclude virus replication by altering cellular potassium ions, a known determinant of LACV entry. We extended these results to other ionophores and found that the antiviral activity of valinomycin extended to other viral families including bunyaviruses (Rift Valley fever virus, Keystone virus), enteroviruses (Coxsackievirus, rhinovirus), flavirivuses (Zika), and coronaviruses (229E and MERS-CoV). In all viral infections, we observed significant reductions in virus titer in valinomycin-treated cells. In sum, we demonstrate the importance of potassium ions to virus infection, suggesting a potential therapeutic target to disrupt virus replication.ImportanceNo antivirals are approved for the treatment of bunyavirus infection. The ability to rapidly screen compounds and identify novel antivirals is one means to accelerate drug discovery for viruses with no approved treatments. We used this approach to screen hundreds of compounds against La Crosse virus, an emerging bunyavirus that causes significant disease, including encephalitis. We identified several known and previously unidentified antivirals. We focused on a potassium ionophore, valinomycin, due to its promising in vitro antiviral activity. We demonstrate that valinomycin, as well as a selection of other ionophores, exhibits activity against La Crosse virus as well as several other distantly related bunyaviruses. We finally observe that valinomycin has activity against a wide array of human viral pathogens, suggesting that disrupting potassium ion homeostasis with valinomycin may be a potent host pathway to target to quell virus infection.

scholarly journals Polyamine Depletion Inhibits Bunyavirus Infection via Generation of Noninfectious Interfering Virions

2019 ◽  
Vol 93 (14) ◽  
Author(s):  
Vincent Mastrodomenico ◽  
Jeremy J. Esin ◽  
Marion L. Graham ◽  
Patrick M. Tate ◽  
Grant M. Hawkins ◽  
...  
Keyword(s):  
Virus Replication ◽  
Rift Valley Fever Virus ◽  
Productive Infection ◽  
Protein Accumulation ◽  
La Crosse Virus ◽  
Innate Immune Responses ◽  
Viral Pathogens ◽  
Valley Fever ◽  
Hemorrhagic Fevers ◽  
Viral Particles

ABSTRACTSeveral host and viral processes contribute to forming infectious virions. Polyamines are small host molecules that play diverse roles in viral replication. We previously demonstrated that polyamines are crucial for RNA viruses; however, the mechanisms by which polyamines function remain unknown. Here, we investigated the role of polyamines in the replication of the bunyaviruses Rift Valley fever virus (vaccine strain MP-12) and La Crosse virus (LACV). We found that polyamine depletion did not impact viral RNA or protein accumulation, despite significant decreases in titer. Viral particles demonstrated no change in morphology, size, or density. Thus, polyamine depletion promotes the formation of noninfectious particles. These particles interfere with virus replication and stimulate innate immune responses. We extended this phenotype to Zika virus; however, coxsackievirus did not similarly produce noninfectious particles. In sum, polyamine depletion results in the accumulation of noninfectious particles that interfere with replication and stimulate immune signaling, with important implications for targeting polyamines therapeutically, as well as for vaccine strategies.IMPORTANCEBunyaviruses are emerging viral pathogens that cause encephalitis, hemorrhagic fevers, and meningitis. We have uncovered that diverse bunyaviruses require polyamines for productive infection. Polyamines are small, positively charged host-derived molecules that play diverse roles in human cells and in infection. In polyamine-depleted cells, bunyaviruses produce an overabundance of noninfectious particles that are indistinguishable from infectious particles. However, these particles interfere with productive infection and stimulate antiviral signaling pathways. We further find that additional enveloped viruses are similarly sensitive to polyamine depletion but that a nonenveloped enterovirus is not. We posit that polyamines are required to maintain bunyavirus infectivity and that polyamine depletion results in the accumulation of interfering noninfectious particles that limit infectivity. These results highlight a novel means by which bunyaviruses use polyamines for replication and suggest promising means to target host polyamines to reduce virus replication.

scholarly journals Novel Antiviral Characteristics of Nanosized Copper(I) Iodide Particles Showing Inactivation Activity against 2009 Pandemic H1N1 Influenza Virus

2011 ◽  
Vol 78 (4) ◽  
pp. 951-955 ◽  
Author(s):  
Yoshie Fujimori ◽  
Tetsuya Sato ◽  
Taishi Hayata ◽  
Tomokazu Nagao ◽  
Mikio Nakayama ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Hydroxyl Radicals ◽  
Influenza A ◽  
Virus Titer ◽  
H1n1 Influenza ◽  
Radical Scavenger ◽  
Dependent Manner ◽  
Pandemic H1n1 ◽  
Titration Assay ◽  
Average Size

ABSTRACTWe investigated the antiviral activity of nanosized copper(I) iodide (CuI) particles having an average size of 160 nm. CuI particles showed aqueous stability and generated hydroxyl radicals, which were probably derived from monovalent copper (Cu+). We confirmed that CuI particles showed antiviral activity against an influenza A virus of swine origin (pandemic [H1N1] 2009) by plaque titration assay. The virus titer decreased in a dose-dependent manner upon incubation with CuI particles, with the 50% effective concentration being approximately 17 μg/ml after exposure for 60 min. SDS-PAGE analysis confirmed the inactivation of the virus due to the degradation of viral proteins such as hemagglutinin and neuraminidase by CuI. Electron spin resonance (ESR) spectroscopy revealed that CuI generates hydroxyl radicals in aqueous solution, and radical production was found to be blocked by the radical scavengerN-acetylcysteine. Taken together, these findings indicate that CuI particles exert antiviral activity by generating hydroxyl radicals. Thus, CuI may be a useful material for protecting against viral attacks and may be suitable for applications such as filters, face masks, protective clothing, and kitchen cloths.

scholarly journals Virion-associated spermidine transmits with Rift Valley fever virus particles to maintain infectivity

2020 ◽  
Author(s):  
Vincent Mastrodomenico ◽  
Jeremy J. Esin ◽  
Shefah Qazi ◽  
Oreoluwa S. Omoba ◽  
Brittany L. Fung ◽  
...  
Keyword(s):  
Virus Replication ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Rna Virus ◽  
Rift Valley Fever Virus ◽  
Acid Synthesis ◽  
Fever Virus ◽  
Virus Infectivity ◽  
Cellular Functions ◽  
Valley Fever

AbstractViruses require host cell metabolites to productively infect, and the mechanisms by which viruses usurp these molecules is diverse. One group of cellular metabolites important in virus infection is the polyamines, small positively-charged molecules involved in cell cycle, translation, and nucleic acid synthesis, among other cellular functions. Polyamines also support replication of diverse viruses, and they are important for processes such as transcription, translation, and viral protein enzymatic activity. Rift Valley fever virus (RVFV) is a negative-sense RNA virus that requires polyamines to produce infectious particles. In polyamine depleted conditions, noninfectious particles are produced that interfere with virus replication and stimulate immune signaling. Here, we find that RVFV relies on virion-associated polyamines to maintain infectivity. We show that RVFV replication is facilitated by any of the three biogenic polyamines; however, we specifically find spermidine associated with purified virions. Using a panel of polyamine homologs, we observe that virions can also associate with (R)-3-methylspermidine and norspermidine, though not with other less homologous molecules. Using polyamine reporter cells, we demonstrate that virion-associated polyamines transmit from one infected cell to another. Finally, we find that virions devoid of polyamines are unstable and cannot be supplemented with exogenous polyamines to regain stability or infectivity. These data highlight a unique role for polyamines, and spermidine in particular, in maintaining virus infectivity, a function not previously appreciated. Further, these studies are the first to identify polyamines associated with RVFV virions. Targeting polyamines represents a promising antiviral strategy, and this work highlights a new mechanism by which we can inhibit virus replication through FDA-approved polyamine depleting pharmaceuticals.

scholarly journals A Genome-Wide CRISPR-Cas9 Screen Reveals the Requirement of Host Cell Sulfation for Schmallenberg Virus Infection

2020 ◽  
Vol 94 (17) ◽  
Author(s):  
Thiprampai Thamamongood ◽  
Andrea Aebischer ◽  
Valentina Wagner ◽  
Max W. Chang ◽  
Roland Elling ◽  
...  
Keyword(s):  
Cell Surface ◽  
Heparan Sulfate ◽  
Host Cell ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Schmallenberg Virus ◽  
La Crosse Virus ◽  
Valley Fever ◽  
Genome Wide

ABSTRACT Schmallenberg virus (SBV) is an insect-transmitted orthobunyavirus that can cause abortions and congenital malformations in the offspring of ruminants. Even though the two viral surface glycoproteins Gn and Gc are involved in host cell entry, the specific cellular receptors of SBV are currently unknown. Using genome-wide CRISPR-Cas9 forward screening, we identified 3′-phosphoadenosine 5′-phosphosulfate (PAPS) transporter 1 (PAPST1) as an essential factor for SBV infection. PAPST1 is a sulfotransferase involved in heparan sulfate proteoglycan synthesis encoded by the solute carrier family 35 member B2 gene (SLC35B2). SBV cell surface attachment and entry were largely reduced upon the knockout of SLC35B2, whereas the reconstitution of SLC35B2 in these cells fully restored their susceptibility to SBV infection. Furthermore, treatment of cells with heparinase diminished infection with SBV, confirming that heparan sulfate plays an important role in cell attachment and entry, although to various degrees, heparan sulfate was also found to be important to initiate infection by two other bunyaviruses, La Crosse virus and Rift Valley fever virus. Thus, PAPST1-triggered synthesis of cell surface heparan sulfate is required for the efficient replication of SBV and other bunyaviruses. IMPORTANCE SBV is a newly emerging orthobunyavirus (family Peribunyaviridae) that has spread rapidly across Europe since 2011, resulting in substantial economic losses in livestock farming. In this study, we performed unbiased genome-wide CRISPR-Cas9 screening and identified PAPST1, a sulfotransferase encoded by SLC35B2, as a host entry factor for SBV. Consistent with its role in the synthesis of heparan sulfate, we show that this activity is required for efficient infection by SBV. A comparable dependency on heparan sulfate was also observed for La Crosse virus and Rift Valley fever virus, highlighting the importance of heparan sulfate for host cell infection by bunyaviruses. Thus, the present work provides crucial insights into virus-host interactions of important animal and human pathogens.

scholarly journals Infectious Lassa Virus, but Not Filoviruses, Is Restricted by BST-2/Tetherin

2010 ◽  
Vol 84 (20) ◽  
pp. 10569-10580 ◽  
Author(s):  
Sheli R. Radoshitzky ◽  
Lian Dong ◽  
Xiaoli Chi ◽  
Jeremiah C. Clester ◽  
Cary Retterer ◽  
...  
Keyword(s):  
Lake Victoria ◽  
Rift Valley Fever Virus ◽  
Nipah Virus ◽  
Cellular Membrane ◽  
Inhibitory Effect ◽  
Lassa Virus ◽  
Cowpox Virus ◽  
Human Pathogens ◽  
Valley Fever ◽  
The Matrix

ABSTRACT Bone marrow stromal antigen 2 (BST-2/tetherin) is a cellular membrane protein that inhibits the release of HIV-1. We show for the first time, using infectious viruses, that BST-2 also inhibits egress of arenaviruses but has no effect on filovirus replication and spread. Specifically, infectious Lassa virus (LASV) release significantly decreased or increased in human cells in which BST-2 was either stably expressed or knocked down, respectively. In contrast, replication and spread of infectious Zaire ebolavirus (ZEBOV) and Lake Victoria marburgvirus (MARV) were not affected by these conditions. Replication of infectious Rift Valley fever virus (RVFV) and cowpox virus (CPXV) was also not affected by BST-2 expression. Elevated cellular levels of human or murine BST-2 inhibited the release of virus-like particles (VLPs) consisting of the matrix proteins of multiple highly virulent NIAID Priority Pathogens, including arenaviruses (LASV and Machupo virus [MACV]), filoviruses (ZEBOV and MARV), and paramyxoviruses (Nipah virus). Although the glycoproteins of filoviruses counteracted the antiviral activity of BST-2 in the context of VLPs, they could not rescue arenaviral (LASV and MACV) VLP release upon BST-2 overexpression. Furthermore, we did not observe colocalization of filoviral glycoproteins with BST-2 during infection with authentic viruses. None of the arenavirus-encoded proteins rescued budding of VLPs in the presence of BST-2. Our results demonstrate that BST-2 might be a broad antiviral factor with the ability to restrict release of a wide variety of human pathogens. However, at least filoviruses, RVFV, and CPXV are immune to its inhibitory effect.

scholarly journals Combination Kinase Inhibitor Treatment Suppresses Rift Valley Fever Virus Replication

Viruses ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 191 ◽  
Author(s):  
Todd Bell ◽  
Virginia Espina ◽  
Lindsay Lundberg ◽  
Chelsea Pinkham ◽  
Ashwini Brahms ◽  
...  
Keyword(s):  
Virus Replication ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Kinase Inhibitor ◽  
Rift Valley Fever Virus ◽  
Fever Virus ◽  
Valley Fever ◽  
Inhibitor Treatment

scholarly journals Modification of the Host Cell Lipid Metabolism Induced by Hypolipidemic Drugs Targeting the Acetyl Coenzyme A Carboxylase Impairs West Nile Virus Replication

2015 ◽  
Vol 60 (1) ◽  
pp. 307-315 ◽  
Author(s):  
Teresa Merino-Ramos ◽  
Ángela Vázquez-Calvo ◽  
Josefina Casas ◽  
Francisco Sobrino ◽  
Juan-Carlos Saiz ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Virus Replication ◽  
Coenzyme A ◽  
Viral Infections ◽  
Lipid Synthesis ◽  
Dependent Manner ◽  
West Nile ◽  
Acetyl Coa ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme

ABSTRACTWest Nile virus (WNV) is a neurotropic flavivirus transmitted by the bite of mosquitoes that causes meningitis and encephalitis in humans, horses, and birds. Several studies have highlighted that flavivirus infection is highly dependent on cellular lipids for virus replication and infectious particle biogenesis. The first steps of lipid synthesis involve the carboxylation of acetyl coenzyme A (acetyl-CoA) to malonyl-CoA that is catalyzed by the acetyl-CoA carboxylase (ACC). This makes ACC a key enzyme of lipid synthesis that is currently being evaluated as a therapeutic target for different disorders, including cancers, obesity, diabetes, and viral infections. We have analyzed the effect of the ACC inhibitor 5-(tetradecyloxy)-2-furoic acid (TOFA) on infection by WNV. Lipidomic analysis of TOFA-treated cells confirmed that this drug reduced the cellular content of multiple lipids, including those directly implicated in the flavivirus life cycle (glycerophospholipids, sphingolipids, and cholesterol). Treatment with TOFA significantly inhibited the multiplication of WNV in a dose-dependent manner. Further analysis of the antiviral effect of this drug showed that the inhibitory effect was related to a reduction of viral replication. Furthermore, treatment with another ACC inhibitor, 3,3,14,14-tetramethylhexadecanedioic acid (MEDICA 16), also inhibited WNV infection. Interestingly, TOFA and MEDICA 16 also reduced the multiplication of Usutu virus (USUV), a WNV-related flavivirus. These results point to the ACC as a druggable cellular target suitable for antiviral development against WNV and other flaviviruses.

scholarly journals Interferon in experimental viral infections in mice: tissue interferon levels resulting from the virus infection and from exogenous interferon therapy

1980 ◽  
Vol 30 (2) ◽  
pp. 513-522
Author(s):  
H Heremans ◽  
A Billiau ◽  
P De Somer
Keyword(s):  
Antiviral Activity ◽  
Viral Replication ◽  
Vaccinia Virus ◽  
Virus Replication ◽  
Viral Infections ◽  
Acute Infection ◽  
Small Doses ◽  
Mengo Virus ◽  
Low Levels ◽  
The Brain

In mice given single intraperitoneal doses of interferon, serum interferon levels peaked at 1 h postinjection and were reduced to zero at about 8 h. The interferon concentrations in spleen, liver, and lungs were about 100-fold higher than could be expected from the amount of serum contained in these organs. In the brain only low levels of antiviral activity were detected. In mice infected intraperitoneally with Mengo virus, viral replication in the brain occurred around day 4 and was accompanied by the appearance of large amounts of interferon (approximately 10(3.25) U/g). This was preceded, however, by viral replication in the spleen and by the appearance of modest amounts of interferon in spleen and serum. In these mice protection could be obtained with relatively small doses of interferon, provided protection could be obtained with relatively small doses of interferon, provided they were given before the time of maximal levels of endogenous serum interferon. In mice infected intranasally with vesicular stomatitis virus, virus replication in the brain started within 24 to 48 h and increased with time; also, small amounts of interferon (10(2) to 10(2.5) U/g) were already detectable on days 1 and 2. The major peak of virus replication in the brain occurred on days 5 to 6 and was accompanied by the appearance of large amounts of interferon (approximately 10(3.25) U/g). In this model early treatment with interferon also provided protection, but only if given in larger doses than in the Mengo virus system. Athymic (nu/nu) mice developed a chronic systemic infection when inoculated with a demotropic strain of vaccinia virus. No interferon was detected in sera, livers, spleens, or lungs of these animals; some mice had low levels of interferon-like antiviral activity in the brain, but no attempt was made to characterize this material. Daily administration of large doses of interferon failed to exert an effect on the development of this chronic disease. Yet, normal (NMRI) mice were protected against acute infection with dermotropic or neurotropic strains of vaccinia virus, and athymic mice were partially protected against acute lethal infection with neurotropic vaccinia virus.

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