qHTS for Stage-Specific Inhibitors of Vaccinia Orthopoxvirus: mCherry Reporter Primary qHTS
Orthopoxviruses are a genus of viruses that include monkeypox, variola (the causative agent of smallpox) and vaccinia, the prototypical orthopoxvirus which was used in the world-wide vaccination program that eradicated smallpox . Smallpox was once the most deadly human pathogen, and is estimated to have killed more than 300 million people. Following the eradication of smallpox, routine more ..
BioActive Compounds: 1931
Orthopoxviruses are a genus of viruses that include monkeypox, variola (the causative agent of smallpox) and vaccinia, the prototypical orthopoxvirus which was used in the world-wide vaccination program that eradicated smallpox . Smallpox was once the most deadly human pathogen, and is estimated to have killed more than 300 million people. Following the eradication of smallpox, routine vaccination was discontinued in the 1970s, and there has consequently been a precipitous decline in population immunity to smallpox and other orthopoxviruses. There are currently no FDA-licensed drugs to treat infected individuals, which is a significant concern given the threat of orthopoxvirus weaponization and the rise in reports of humans infected with monkeypox, which is endemic to Central and Western Africa . Potent and validated inhibitors of this assay will be of significant interest to public and will provide the development of initial compound leads into therapeutic agents, either as a single agent or as a combination therapy with existing anti-viral agents.
In collaboration with the Connor lab, a quantitative high throughput assay using vaccinia virus model system was developed. The assay used recombinant viruses (coupled reporter system) that robustly monitor viral gene expression and viral spread to identify novel anti-orthopoxviral compounds. The first infection evaluates the stage gene expression in Vaccinia using the fluorescent Venus protein while the late infection uses the fluorescent mCherry protein reporter. The data herein is the result of the primary screen using the mCherry protein reporter. Decrease in signal in both reporters, indicative of orthopoxvirus inhibition is the desired outcome for this assay.
NIH Chemical Genomics Center [NCGC]
NIH Molecular Libraries Probe Centers Network [MLPCN]
MLPCN Grant: MH094169
Assay Submitter (PI): John Connor, Boston University
 Moss B (2007) Poxviridae: The Viruses and Their Replication. In: Knipe DMH, P.M., editor. Fields Virology. 5 ed: Lippincott Williams & Wilkins.
 Rimoin AW, Kisalu N, Kebela-Ilunga B, Mukaba T, Wright LL et al. (2007) Endemic human monkeypox, Democratic Republic of Congo, 2001-2004. Emerg Infect Dis 13(6): 934-937
A549 cells were plated at a concentration of approximately 6,000 cells per well in clear-bottom black-walled plates. Compounds were added to the assay plate followed by addition of virus (LREV) that expresses the Venus fluorescent protein early in viral ininfection. During the late viral infection, mCherry was also added to the plate at an MOI of 10 (~ 60,000 plaque forming units (PFU) of virus). Following virus addition, plates were incubated in a tissue-culture incubator for 12-18 hours. At increasing times postinfection, fluorescence from both Venus and mCherrry was determined using a plate-reader and standard conditions for observing Venus fluorescence (EX515/EM530) and mCherry fluorescence (EX587/EM610). In each plate, positive controls (virus infection in the presence of 1% DMSO only) and an inhibitory drug control (AraC at 500 nM) was included and used to normalize the data.
1. Compounds are first classified as having full titration curves, partial modulation, partial curve (weaker actives), single point activity (at highest concentration only), or inactive. See data field "Curve Description". For this assay, apparent inhibitors are ranked higher than compounds that showed apparent activation.
2. For all inactive compounds, PUBCHEM_ACTIVITY_SCORE is 0. For all active compounds, a score range was given for each curve class type given above. Active compounds have PUBCHEM_ACTIVITY_SCORE between 40 and 100. Inconclusive compounds have PUBCHEM_ACTIVITY_SCORE between 1 and 39. Fit_LogAC50 was used for determining relative score and was scaled to each curve class' score range.
* Activity Concentration. ** Test Concentration.
Data Table (Concise)