Biology subjects

Boggs, E. A.

Publications and source records attributed to Boggs, E. A..

3 recordsLinked to original sources

bioRxiv2023

Mpox Virus is Inhibited By Nucleoside Analogues Including the Acyclic Phosphonates Tenofovir and Adefovir

Mpox virus (MPXV) is an orthopoxvirus that causes the human disease mpox, which is characterized by fever, myalgia, and formation of rashes and lesions, and which garnered worldwide attention due to a global outbreak in 2022. In response to the outbreak, the antivirals tecovirimat, cidofovir, and brincidofovir have been used as emergency treatment for mpox. However, because of drug resistance and toxicity risks with those compounds, there is still a need for additional antivirals to treat orthopoxvirus diseases. Since cidofovir is a nucleoside analogue, we investigated a selection of other such compounds for antiviral activity against orthopoxviruses. We developed in vitro screening assays using fluorescent strains of vaccinia virus (VACV) and modified vaccinia Ankara (MVA) to measure the antiviral potency of test compounds. We found that tenofovir alafenamide and adefovir dipixovil, both acyclic phosphonates, had strong potential combinations of anti-orthopoxvirus activity and low toxicity after testing them against MVA and VACV, with EC50 values in the single digit micromolar and nanomolar range, while other potential hits included trifluridine and two arabinosides. We then recapitulated the results with MPXV using a luciferase-based assay. These data reinforce the interest of repurposing nucleoside analogues as antivirals to treat poxvirus infections and provide a basis for high throughput screening and mechanistic and antiviral resistance studies.

microbiology↗

bioRxiv2021

Subgenomic SARS-CoV-2 replicon and reporter replicon cell lines enable ultrahigh throughput antiviral screening and mechanistic studies with antivirals, viral mutations or host factors that affect COVID-19 replication

Replicon-based technologies were used to develop reagents and assays for advanced drug discovery efforts against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and for examining all facets of the SARS-CoV-2 replication cycle at reduced biocontainment level. Specifically: a) 21 replicons were cloned in bacterial artificial chromosomes (BACs) and delivered as transfectable plasmid DNA or transcribed RNA in various cell types. Replicons carrying mutations that affect the activity or antiviral susceptibility of SARS-CoV-2 enzymes were used to establish utility for mechanistic studies while reducing the community risks associated with gain-of-function studies in fully infectious virus. b) A BHK-21 stable cell line harboring SARS-CoV-2 replicon was generated and characterized in robust high/ultra-high throughput assays of antiviral efficacy with orthogonal SARS-CoV-2 replication reporter genes (Nano luciferase and enhanced green fluorescent protein-eGFP); the estimated antiviral potencies in the fully infectious SARS-CoV-2 system and in the transient or stable replicon systems were similar. HEK293 and Calu1 stable cell lines expressing SARS-CoV-2 replicon have also been prepared. Finally, c) we generated trans-encapsidated replicons by co-expression with SARS-CoV-2 structural proteins, thus producing single-round infectious SARS-CoV-2 virus-like particles that are able to transduce susceptible cell types and have expanded utility to enable study of virion assembly and entry into target cells. Hence, these SARS-CoV-2 replicon-based reagents include a novel approach to replicon-harboring cell line generation and are valuable tools that can be used at lower biosafety level (BSL2) for drug discovery efforts, characterization of SARS-CoV-2 and variant evolution in the COVID-19 pandemic, mechanisms of inhibition and resistance, and studies on the role of SARS-CoV-2 genes and host dependency factors.

microbiology↗

bioRxiv2020

Cytoplasmic CPSF6 regulates HIV-1 capsid trafficking and infection in a cyclophilin A-dependent manner

Human immunodeficiency virus type 1 (HIV-1) capsid binds host proteins during infection, including cleavage and polyadenylation specificity factor 6 (CPSF6) and cyclophilin A (CypA). We observe that HIV-1 infection induces higher-order CPSF6 formation and capsid-CPSF6 complexes co-traffic on microtubules. CPSF6-capsid complex trafficking is impacted by capsid alterations that reduce CPSF6 binding or by excess cytoplasmic CPSF6 expression, both of which are associated with decreased HIV-1 infection. Higher-order CPSF6 complexes bind and disrupt HIV-1 capsid assemblies in vitro. Disruption of HIV-1 capsid binding to CypA leads to increased CPSF6 binding and altered capsid trafficking, resulting in reduced infectivity. Our data reveal an interplay between CPSF6 and CypA that is important for cytoplasmic capsid trafficking and HIV-1 infection. We propose that CypA prevents HIV-1 capsid from prematurely engaging cytoplasmic CPSF6 and that differences in CypA cellular localization and innate immunity may explain cell-specific variations in HIV-1 capsid trafficking and uncoating. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=131 SRC="FIGDIR/small/136697v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@646829org.highwire.dtl.DTLVardef@1f25cf9org.highwire.dtl.DTLVardef@b5e696org.highwire.dtl.DTLVardef@3593a7_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗