The Antifungal Itraconazole Is a Potent Inhibitor of Chikungunya Virus Replication

Abstract

Chikungunya virus (CHIKV) is the causative agent of chikungunya fever, a disabling disease that can cause long-term severe arthritis. Since the last large CHIKV outbreak in 2015, the reemergence of the virus represents a serious public health concern. The morbidity associated with viral infection emphasizes the need for the development of specific anti-CHIKV drugs. Herein, we describe the development and characterization of a CHIKV reporter replicon cell line and its use in replicon-based screenings. We tested 960 compounds from MMV/DNDi Open Box libraries and identified four candidates with interesting antiviral activities, which were confirmed in viral infection assays employing CHIKV-nanoluc and BHK-21 cells. The most noteworthy compound identified was itraconazole (ITZ), an orally available, safe, and cheap antifungal, that showed high selectivity indexes of >312 and >294 in both replicon-based and viral infection assays, respectively. The antiviral activity of this molecule has been described against positive-sense single stranded RNA viruses (+ssRNA) and was related to cholesterol metabolism that could affect the formation of the replication organelles. Although its precise mechanism of action against CHIKV still needs to be elucidated, our results demonstrate that ITZ is a potent inhibitor of the viral replication that could be repurposed as a broad-spectrum antiviral.

New highly selective antivirals for Chikungunya Virus identified from the screening of a drug-like compound library

“…2c). According to previous results, the antimalarial MMV000008 (Chloroquine) [22] and the broad spectrum indirect antiviral agent MMV690621 (GSK-983) [19,23,24] presented potent anti CHIKV activity and high selectivity, with EC50 values in the low micromolar and nanomolar range, respectively (Fig. 3).…”

“…Accordingly, our screening approach successfully identified previously reported CHIKV antiviral compounds in the PRB and further expanded potentially active hits to compounds that presumably target steps in the replication cycle that involve the function of structural proteins. Among the compounds that resulted active in the primary and secondary screening, MMV690621 was previously reported to have anti-CHIKV activity in the subgenomic replicon-based assays reported by Policastro et al [19], and MMV000008 (Chloroquine) was previously shown to inhibit virus entry and release [22]. Overall, our approach using fFFU reduction of CHIKV-ZsGreen as a screening method effectively identified compounds active against CHIKV.…”

“…The present work identified and validated 4 new molecules within the Pandemic Response Box as potential drug candidates against CHIKV: MMV1634402, MMV102270, MMV689401, and MMV1578574. In a previously reported screening of PRB compounds for antiviral activity against CHIKV, Policastro et al [19] confirmed the activity of one compound which was identified following a screening strategy that used a cell line that stably expresses a CHIKV subgenomic replicon encoding viral proteins nsp1-nsp4 and a luciferase reporter gene. This system allowed sensitive identification of molecules that interfere with translation and genome amplification directed by non-coding regions and non-structural proteins.…”

“…Various international non-profit organizations offer large libraries of molecules for hit There is a previous report [19] where three compounds within the PRB were identified as antiviral hits against CHIKV following a subgenomic reporter-based primary screening, after which the antiviral activity of one of them (MMV690621 -GSK-983-) was confirmed. Here, we report the screen of the PRB library against a fully infectious CHIKV reporter virus.…”

Direct-Acting Antivirals and Host-Targeting Approaches against Enterovirus B Infections: Recent Advances

“…Itraconazole is a promiscuous anti-cancer and anti-fungal compound identified in different repurposing screenings as a broad-spectrum antiviral agent [ 95 , 96 , 97 ]. As mentioned in Section 2.2.3 , itraconazole interferes with enteroviral replication independently from its anti-fungal and anti-cancer activities and is inactive against 3A-resistant mutants, suggesting 3A as a potential target.…”