A bifunctional anti-enterovirus compound that inhibits replication and the early stage of enterovirus 71 infection

Abstract

Enviroxime is an anti-enterovirus compound that targets viral protein 3A and/or 3AB and suppresses a replication step of enterovirus by an unknown mechanism. To date, a number of anti-enterovirus compounds that have little structural similarity to enviroxime but induce common resistance mutations in the 3A-encoding region have been identified. The present study identified a novel type of functionally enviroxime-like compound, AN-12-H5. This compound had no structural similarity to enviroxime or to known enviroxime-like compounds, including TTP-8307, GW5074 and Flt3 Inhibitor II. A resistance phenotype of poliovirus (PV) to these compounds was conferred by a major enviroxime-resistance mutation of PV (G5318A, 3A-Ala70Thr), but not by resistance mutations to guanidine hydrochloride and brefeldin A. AN-12-H5 had a common structure with the anti-enterovirus 71 (EV71) compound AN-23-F6. AN-12-H5 and AN-23-F6 inhibited an early stage of EV71 infection after virus binding to the cells. Mutations in capsid proteins (G3112A, VP1-Ala224Thr, and G2396A, VP3-Arg227Lys mutations) were determined as resistant mutations to in the early stage of EV71 infection. These results suggest that AN-12-H5 is a bifunctional anti-enterovirus compound that belongs to a novel class of enviroxime-like compounds and targets both a replication step and an early stage of EV71 infection.

New Small-Molecule Inhibitors Effectively Blocking Picornavirus Replication

“…We found that the viral RNAs from both plaques contained one nucleotide substitution, G5318A, resulting in an amino acid change from alanine to threonine in the 3A sequence. The same mutation was reported previously to confer resistance to a diverse class of so-called enviroxime-like compounds, believed to target a PI4KIII␤-dependent step in the viral replication cycle (10,(43)(44)(45)(46). We confirmed that this mutation was responsible for the resistance to E7(2) by genetically engineering the corresponding change into the poliovirus genome (not shown).…”

Oxysterol-Binding Protein Family I Is the Target of Minor Enviroxime-Like Compounds

“…Moderate anti-HCV activity was observed for enviroxime at high concentrations, consistent with a recent report (23), possibly due to its nonspecific anti-PI4KA activity. These results suggested that T-00127-HEV2 is a novel minor enviroxime-like compound, along with AN-12-H5 (22,36).…”

“…Recently, itraconazole was identified as another minor enviroxime-like compound (37). The characteristic properties of minor enviroxime-like compounds are (i) weak resistance of a PV mutant with a G5318A mutation compared to that observed for the major group (around 5-fold increase of PV replication versus Ͼ50-fold increase of PV replication) and (ii) anti-hepatitis C virus (HCV) activity (22,36). This suggested a common replication pathway inhibited by minor enviroxime-like compounds in enterovirus and HCV, possibly related to PI4P production, which depends on different PI4 kinases: PI4KB in enterovirus and PI4KA in HCV replication (20,22,38,39).…”

“…As a candidate compound of capsid-binding inhibitors, the effectiveness of V-073 (previously designated SCH 48973) on in vitro PV infection and in a mouse infection model has been intensively analyzed in terms of the resistant mutation, pathogenicity of resistant mutants, and effects on immunization with IPV (28)(29)(30)(31)(32). To date, several enviroxime-like compounds have been identified, including TTP-8307 (33), some cellular protein kinase inhibitors (GW5074 and Flt3 inhibitor II) (34,35), and a bifunctional antienterovirus compound, AN-12-H5, which targets the replication process of PV and enterovirus 71 (EV71) and also an early stage of EV71 infection (36). Enviroxime-like compounds can be classified into at least 2 different groups; the majority of identified enviroxime-like compounds are PI4KB inhibitors (e.g., enviroxime, PIK93, GW5074, and T-00127-HEV1 {3- (3,4-…”

Fitness and Virulence of a Coxsackievirus Mutant That Can Circumnavigate the Need for Phosphatidylinositol 4-Kinase Class III Beta

“…Drugs that target host factors that are crucial for virus replication are believed to impede this process. In recent years, several studies identified the essential membrane-modifying host cell factor phosphatidylinositol-4-kinase III␤ (PI4KIII␤) as the target of broad-spectrum and highly potent inhibitors of enterovirus replication (1)(2)(3)(4)(5)(6)(7)(8). However, following lengthy selection processes, coxsackievirus B3 (CVB3) mutants that are resistant to these inhibitors emerged and were shown to harbor single point mutations in the nonstructural protein 3A (4,7,8).…”