Effectiveness of sub‐therapeutic staurosporine on inhibition of budding and replication of lipid‐enveloped viruses

Infectious Diseases are a major cause of morbidity and mortality internationally, disproportionately affecting developing countries. Many of the deficits caused by infectious diseases are due to viruses, specifically lipid‐enveloped viruses. By identifying a common infectious pathway via viral phosphatidylserine (PS) to host TIM protein receptor and a class of drug that was recently found to potentially interfere with this common pathway, it was hypothesized that staurosporines, specifically UCN‐01, can inhibit viral infection and replication of lipid‐enveloped viruses dependent on viral PS and host TIM receptor interactions, including but not limited to Ebola virus, Marburg virus, HIV‐1, Dengue virus, Chikungunya virus, and Zika virus. The effects of UCN‐01 on the effects of PS localization in mammalian cells, the effects of UCN‐01 on GFP tagged viral matrix proteins in cell culture, and the efficacy of UCN‐01 on live virus infected cells are being studied. It was shown using confocal microscopy that UCN‐01 is able to significantly reduce plasma membrane localization of both ebola VP40 and HIV‐gag proteins in HEK cells. Flow cytometry was also performed on samples under the same experimental conditions showing alterations in external cell membrane PS expression and drug toxicity over a range of concentrations. This pathway was further supported by previous work done in this lab by showing that Ebola VP40 protein induces PS expression in a cell culture model by using confocal microscopy and flow cytometry. By testing UCN‐01 to determine cell toxicity using Caspase 3 and MTT assays, the dosing used in these experiments were shown to affect cellular metabolism, but at sub‐lethal levels to the cells. By investigating how UCN‐01 affects cell lipidomics using mass spectrometry, more can be understood about the mechanism of action of these drugs interfering with PS and their appropriateness for pursuing as broad class antivirals. In addition, UCN‐01 will be studied in how it can interfere with virus like particle production. After showing efficacy at sub‐toxic levels in the matrix protein model, live virus studies were initiated and have already shown complete viral infectivity inhibition using low MOIs of Dengue virus using TCID‐50 assays. These studies, if successful at decreasing infectivity or viral replication, could lead into future animal model studies that may be taken into clinical trials, producing a broad‐spectrum anti‐viral therapy that would have the potential to eliminate a large portion of the global health burden. Support or Funding Information Fellowship provided by University of Notre Dame Eck Institute for Global Health