scholarly journals 4′-Fluorouridine is an oral antiviral that blocks respiratory syncytial virus and SARS-CoV-2 replication

Science ◽  
2022 ◽  
Vol 375 (6577) ◽  
pp. 161-167
Author(s):  
Julien Sourimant ◽  
Carolin M. Lieber ◽  
Megha Aggarwal ◽  
Robert M. Cox ◽  
Josef D. Wolf ◽  
...  

Preparing antiviral defenses Antiviral drugs are an important tool in the battle against COVID-19. Both remdesivir and molnupiravir, which target the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase, were first developed against other RNA viruses. This highlights the importance of broad-spectrum antivirals that can be rapidly deployed against related emerging pathogens. Sourimant et al . used respiratory syncytial virus (RSV) as a primary indication in identifying further drugs that target the polymerase enzyme of RNA viruses. The authors explored derivatives of molnupiravir and identified 4′ fluorouridine (EIDD-2749) as an inhibitor of the polymerase of RSV and SARS-CoV-2. This drug can be delivered orally and was effective against RSV in mice and SARS-CoV-2 in ferrets. —VV

2020 ◽  
Vol 144 (8) ◽  
pp. 920-928 ◽  
Author(s):  
David A. Schwartz ◽  
Amareen Dhaliwal

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the agent of coronavirus disease 2019 (COVID-19), is similar to 2 other coronaviruses, SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV), in causing life-threatening maternal respiratory infections and systemic complications. Because of global concern for potential intrauterine transmission of SARS-CoV-2 from pregnant women to their infants, this report analyzes the effects on pregnancy of infections caused by SARS-CoV-2 and other respiratory RNA viruses, and examines the frequency of maternal-fetal transmission with SARS-CoV-2, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), influenza, respiratory syncytial virus (RSV), parainfluenza (HPIV), and metapneumovirus (hMPV). There have been no confirmed cases of intrauterine transmission reported with SARS-CoV-2 or any other coronaviruses—SARS and MERS. Influenza virus, despite causing approximately 1 billion annual infections globally, has only a few cases of confirmed or suspected intrauterine fetal infections reported. Respiratory syncytial virus is an unusual cause of illness among pregnant women, and with the exception of 1 premature infant with congenital pneumonia, no other cases of maternal-fetal infection are described. Parainfluenza virus and hMPV can produce symptomatic maternal infections but do not cause intrauterine fetal infection. In summary, it appears that the absence thus far of maternal-fetal transmission of the SARS-CoV-2 virus during the COVID-19 pandemic is similar to other coronaviruses, and is also consistent with the extreme rarity of suggested or confirmed cases of intrauterine transmission of other respiratory RNA viruses. This observation has important consequences for pregnant women because it appears that if intrauterine transmission of SARS-CoV-2 does eventually occur, it will be a rare event. Potential mechanisms of fetal protection from maternal viral infections are also discussed.


Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 234
Author(s):  
Sarah Al-Beltagi ◽  
Cristian Alexandru Preda ◽  
Leah V. Goulding ◽  
Joe James ◽  
Juan Pu ◽  
...  

The long-term control strategy of SARS-CoV-2 and other major respiratory viruses needs to include antivirals to treat acute infections, in addition to the judicious use of effective vaccines. Whilst COVID-19 vaccines are being rolled out for mass vaccination, the modest number of antivirals in use or development for any disease bears testament to the challenges of antiviral development. We recently showed that non-cytotoxic levels of thapsigargin (TG), an inhibitor of the sarcoplasmic/endoplasmic reticulum (ER) Ca2+ ATPase pump, induces a potent host innate immune antiviral response that blocks influenza A virus replication. Here we show that TG is also highly effective in blocking the replication of respiratory syncytial virus (RSV), common cold coronavirus OC43, SARS-CoV-2 and influenza A virus in immortalized or primary human cells. TG’s antiviral performance was significantly better than remdesivir and ribavirin in their respective inhibition of OC43 and RSV. Notably, TG was just as inhibitory to coronaviruses (OC43 and SARS-CoV-2) and influenza viruses (USSR H1N1 and pdm 2009 H1N1) in separate infections as in co-infections. Post-infection oral gavage of acid-stable TG protected mice against a lethal influenza virus challenge. Together with its ability to inhibit the different viruses before or during active infection, and with an antiviral duration of at least 48 h post-TG exposure, we propose that TG (or its derivatives) is a promising broad-spectrum inhibitor against SARS-CoV-2, OC43, RSV and influenza virus.


2020 ◽  
Vol 95 (1) ◽  
Author(s):  
Dongdong Cao ◽  
Yunrong Gao ◽  
Claire Roesler ◽  
Samantha Rice ◽  
Paul D'Cunha ◽  
...  

ABSTRACT Respiratory syncytial virus (RSV) is a nonsegmented negative-sense (NNS) RNA virus and shares a similar RNA synthesis strategy with other members of NNS RNA viruses, such as measles, rabies virus, and Ebola virus. RSV RNA synthesis is catalyzed by a multifunctional RNA-dependent RNA polymerase (RdRP), which is composed of a large (L) protein that catalyzes three distinct enzymatic functions and an essential coenzyme phosphoprotein (P). Here, we successfully prepared highly pure, full-length, wild-type and mutant RSV polymerase (L-P) complexes. We demonstrated that the RSV polymerase could carry out both de novo and primer-based RNA synthesis. We defined the minimal length of the RNA template for in vitro de novo RNA synthesis using the purified RSV polymerase as 8 nucleotides (nt), shorter than previously reported. We showed that the RSV polymerase catalyzed primer-dependent RNA elongation with different lengths of primers on both short (10-nt) and long (25-nt) RNA templates. We compared the sequence specificity of different viral promoters and identified positions 3, 5, and 8 of the promoter sequence as essential to the in vitro RSV polymerase activity, consistent with the results previously mapped with the in vivo minigenome assay. Overall, these findings agree well with those of previous biochemical studies and extend our understanding of the promoter sequence and the mechanism of RSV RNA synthesis. IMPORTANCE As a major human pathogen, RSV affects 3.4 million children worldwide annually. However, no effective antivirals or vaccines are available. An in-depth mechanistic understanding of the RSV RNA synthesis machinery remains a high priority among the NNS RNA viruses. There is a strong public health need for research on this virus, due to major fundamental gaps in our understanding of NNS RNA virus replication. As the key enzyme executing transcription and replication of the virus, the RSV RdRP is a logical target for novel antiviral drugs. Therefore, exploring the primer-dependent RNA elongation extends our mechanistic understanding of the RSV RNA synthesis. Further fine mapping of the promoter sequence paves the way to better understand the function and structure of the RSV polymerase.


Author(s):  
Einat. B. Vitner ◽  
Roy Avraham ◽  
Hagit Achdout ◽  
Hadas Tamir ◽  
Avi Agami ◽  
...  

AbstractThe need for antiviral drugs is real and relevant. Broad spectrum antiviral drugs have a particular advantage when dealing with rapid disease outbreaks, such as the current COVID-19 pandemic. Since viruses are completely dependent on internal cell mechanisms, they must cross cell membranes during their lifecycle, creating a dependence on processes involving membrane dynamics. Thus, in this study we examined whether the synthesis of glycosphingolipids, biologically active components of cell membranes, can serve as an antiviral therapeutic target. We examined the antiviral effect of two specific inhibitors of GlucosylCeramide synthase (GCS); (i) Genz-123346, an analogue of the FDA-approved drug Cerdelga®, (ii) GENZ-667161, an analogue of venglustat which is currently under phase III clinical trials. We found that both GCS inhibitors inhibit the replication of four different enveloped RNA viruses of different genus, organ-target and transmission route: (i) Neuroinvasive Sindbis virus (SVNI), (ii) West Nile virus (WNV), (iii) Influenza A virus, and (iv) SARS-CoV-2. Moreover, GCS inhibitors significantly increase the survival rate of SVNI-infected mice. Our data suggest that GCS inhibitors can potentially serve as a broad-spectrum antiviral therapy and should be further examined in preclinical and clinical trial. Analogues of the specific compounds tested have already been studied clinically, implying they can be fast-tracked for public use. With the current COVID-19 pandemic, this may be particularly relevant to SARS-CoV-2 infection.One Sentence SummaryAn analogue of Cerdelga®, an FDA-approved drug, is effective against a broad range of RNA-viruses including the newly emerging SARS-CoV-2.


2018 ◽  
Vol 93 (4) ◽  
Author(s):  
Patricia A. Jorquera ◽  
Cynthia Mathew ◽  
Jennifer Pickens ◽  
Colin Williams ◽  
Jasmina M. Luczo ◽  
...  

ABSTRACT Respiratory syncytial virus (RSV) is a leading cause of hospitalization of infants and young children, causing considerable respiratory disease and repeat infections that may lead to chronic respiratory conditions such as asthma, wheezing, and bronchitis. RSV causes ∼34 million new episodes of lower respiratory tract illness (LRTI) in children younger than 5 years of age, with >3 million hospitalizations due to severe RSV-associated LRTI. The standard of care is limited to symptomatic relief as there are no approved vaccines and few effective antiviral drugs; thus, a safe and efficacious RSV therapeutic is needed. Therapeutic targeting of host proteins hijacked by RSV to facilitate replication is a promising antiviral strategy as targeting the host reduces the likelihood of developing drug resistance. The nuclear export of the RSV M protein, mediated by the nuclear export protein exportin 1 (XPO1), is crucial for RSV assembly and budding. Inhibition of RSV M protein export by leptomycin B correlated with reduced RSV replication in vitro. In this study, we evaluated the anti-RSV efficacy of Verdinexor (KPT-335), a small molecule designed to reversibly inhibit XPO1-mediated nuclear export. KPT-335 inhibited XPO1-mediated transport and reduced RSV replication in vitro. KPT-335 was effective against RSV A and B strains and reduced viral replication following prophylactic or therapeutic administration. Inhibition of RSV replication by KPT-335 was due to a combined effect of reduced XPO1 expression, disruption of the nuclear export of RSV M protein, and inactivation of the NF-κB signaling pathway. IMPORTANCE RSV is an important cause of LRTI in infants and young children for which there are no suitable antiviral drugs offered. We evaluated the efficacy of KPT-335 as an anti-RSV drug and show that KPT-335 inhibits XPO1-mediated nuclear export, leading to nuclear accumulation of RSV M protein and reduction in RSV levels. KPT-335 treatment also resulted in inhibition of proinflammatory pathways, which has important implications for its effectiveness in vivo.


2020 ◽  
Vol 222 (7) ◽  
pp. 1090-1097 ◽  
Author(s):  
You Li ◽  
Xin Wang ◽  
Harish Nair

Abstract Background The ongoing pandemic of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could recur as seasonal outbreaks, a circulating pattern observed among other preexisting human seasonal coronaviruses (sCoVs). However, little is known about seasonality of sCoVs on a global scale. Methods We conducted a systematic review of data on seasonality of sCoVs. We compared seasonality of sCoVs with influenza virus and respiratory syncytial virus. We modeled monthly activity of sCoVs using site-specific weather data. Results We included sCoV seasonality data in 40 sites from 21 countries. sCoVs were prevalent in winter months in most temperate sites except for China, whereas sCoVs tended to be less seasonal in China and in tropical sites. In temperate sites excluding China, 53.1% of annual sCoV cases (interquartile range [IQR], 34.6%–61.9%) occurred during influenza season and 49.6% (IQR, 30.2%–60.2%) of sCoV cases occurred during respiratory syncytial virus season. Low temperature combined with high relative humidity was associated with higher sCoV activity. Conclusions This is the first study that provides an overview of the global seasonality of sCoVs. Our findings offer clues to the possible postpandemic circulating season of SARS-CoV-2 and add to the knowledge pool necessary for postpandemic preparedness for SARS-CoV-2.


Sign in / Sign up

Export Citation Format

Share Document