Identification and characterization of bisbenzimide compounds that inhibit human cytomegalovirus replication

Abstract

The shortcomings of current anti-human cytomegalovirus (HCMV) drugs has stimulated a search for anti-HCMV compounds with novel targets. We screened collections of bioactive compounds and identified a range of compounds with the potential to inhibit HCMV replication. Of these compounds, we selected bisbenzimide compound RO-90-7501 for further study. We generated analogues of RO-90-7501 and found that one compound, MRT00210423, had increased anti-HCMV activity compared to RO-90-7501. Using a combination of compound analogues, microscopy and biochemical assays we found RO-90-7501 and MRT00210423 interacted with DNA. In single molecule microscopy experiments we found RO-90-7501, but not MRT00210423, was able to compact DNA, suggesting that compaction of DNA was non-obligatory for anti-HCMV effects. Using bioinformatics analysis, we found that there were many putative bisbenzimide binding sites in the HCMV DNA genome. However, using western blotting, quantitative PCR and electron microscopy, we found that at a concentration able to inhibit HCMV replication our compounds had little or no effect on production of certain HCMV proteins or DNA synthesis, but did have a notable inhibitory effect on HCMV capsid production. We reasoned that these effects may have involved binding of our compounds to the HCMV genome and/or host cell chromatin. Therefore, our data expand our understanding of compounds with anti-HCMV activity and suggest targeting of DNA with bisbenzimide compounds may be a useful anti-HCMV strategy.

Toward inhibition of human cytomegalovirus replication with compounds targeting cellular proteins

“…Therefore, I also advocate considering inhibition of other cellular molecules required for HCMV replication. For example, we have explored inhibition of productive HCMV replication using compounds that appear to interact with cellular DNA in chromatin [64]. Importantly, because interference with the function of viral or cellular DNA may affect the replication of many viruses other than HCMV, the compounds investigated in our aforementioned project [64] have the potential to be used as broad-spectrum antiviral compounds.…”

“…the compound screening experiments mentioned above also identify compounds with anti-HCMV activity whose function in HCMV-infected cells is unclear or unknown [28,[63][64][65], for example the ion channel inhibitor convallatoxin [63] and the natural product moiety deguelin [28,65]. Further investigation of these and other compounds with potential anti-HCMV activity may uncover compounds that have the potential to be developed for clinical use against HCMV.…”

“…Moreover, such is the potential of this machine learning technology to uncover new drug targets, it would be useful to further characterize kinase targets within kinase inhibitor collections already screened for anti-HCMV compounds [73,74] and apply the machine learning approach mentioned above [78] to that data. Indeed, if possible, it would be useful to understand what data can be mined using machine learning from previous screens for anti-HCMV compounds [28,36,38,42,64] and understand how future compound screens can be designed to take advantage of developments in machine learning data analysis.…”

“…However, drugs that inhibit essential cellular processes would probably have significant toxicity in vivo and it is unlikely that they would be administered to the patient populations affected by HCMV disease. It is interesting to note that the compound screening experiments mentioned above also identify compounds with anti-HCMV activity whose function in HCMV-infected cells is unclear or unknown [28, 63–65], for example the ion channel inhibitor convallatoxin [63] and the natural product moiety deguelin [28, 65]. Further investigation of these and other compounds with potential anti-HCMV activity may uncover compounds that have the potential to be developed for clinical use against HCMV.…”

“…that appear to interact with cellular DNA in chromatin [64]. Importantly, because interference with the function of viral or cellular DNA may affect the replication of many viruses other than HCMV, the compounds investigated in our aforementioned project [64] have the potential to be used as broad-spectrum antiviral compounds.…”